diff --git a/lib/Controller/RoomController.php b/lib/Controller/RoomController.php
index ec1d18c3523..cabf5d428b1 100644
--- a/lib/Controller/RoomController.php
+++ b/lib/Controller/RoomController.php
@@ -477,7 +477,7 @@ protected function formatRoomV1(Room $room, ?Participant $currentParticipant): a
 		$numActiveGuests = 0;
 		$cleanGuests = false;
 		$participantList = [];
-		$participants = $this->participantService->getParticipantsForRoom($room, true); // FIXME NEEDS the session but can potentially kill APIv1?
+		$participants = $this->participantService->getSessionsAndParticipantsForRoom($room); // FIXME NEEDS the session but can potentially kill APIv1?
 		uasort($participants, function (Participant $participant1, Participant $participant2) {
 			$s1 = $participant1->getSession() ? $participant1->getSession()->getLastPing() : 0;
 			$s2 = $participant2->getSession() ? $participant2->getSession()->getLastPing() : 0;
@@ -1110,7 +1110,7 @@ public function getParticipants(bool $includeStatus = false): DataResponse {
 		}
 
 		$maxPingAge = $this->timeFactory->getTime() - 100;
-		$participants = $this->participantService->getParticipantsForRoom($this->room, true);
+		$participants = $this->participantService->getSessionsAndParticipantsForRoom($this->room);
 		$results = $headers = $statuses = [];
 
 		if ($this->userId !== null
diff --git a/lib/Manager.php b/lib/Manager.php
index 2f1b848c737..aca843f2881 100644
--- a/lib/Manager.php
+++ b/lib/Manager.php
@@ -317,7 +317,7 @@ public function getRoomsForUser(string $userId, bool $loadSession = false, bool
 			->where($query->expr()->isNotNull('a.id'));
 
 		if ($loadSession) {
-			$helper->selectSessionsTable($query);
+			$helper->selectSessionsTable($query); // FIXME ?
 			$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->andX(
 				$query->expr()->eq('a.id', 's.attendee_id')
 			));
diff --git a/lib/Model/SelectHelper.php b/lib/Model/SelectHelper.php
index ade976f5c19..3bf0463c819 100644
--- a/lib/Model/SelectHelper.php
+++ b/lib/Model/SelectHelper.php
@@ -83,4 +83,17 @@ public function selectSessionsTable(IQueryBuilder $query, string $alias = 's'):
 			->addSelect($alias . 'last_ping')
 			->selectAlias($alias . 'id', 's_id');
 	}
+
+	public function selectSessionsTableMax(IQueryBuilder $query, string $alias = 's'): void {
+		if ($alias !== '') {
+			$alias .= '.';
+		}
+
+		$query->selectAlias($query->func()->max($alias . 'attendee_id'), 'attendee_id')
+			->selectAlias($query->func()->max($alias . 'session_id'), 'session_id')
+			// BIT_OR would be better, but SQLite does not support something like it.
+			->selectAlias($query->func()->max($alias . 'in_call'), 'in_call')
+			->selectAlias($query->func()->max($alias . 'last_ping'), 'last_ping')
+			->selectAlias($query->func()->max($alias . 'id'), 's_id');
+	}
 }
diff --git a/lib/Room.php b/lib/Room.php
index 96140f6af40..664059e4aeb 100644
--- a/lib/Room.php
+++ b/lib/Room.php
@@ -427,13 +427,14 @@ public function getParticipant(?string $userId, $sessionId = null): Participant
 			->setMaxResults(1);
 
 		if ($sessionId !== false) {
-			$helper->selectSessionsTable($query);
 			if ($sessionId !== null) {
+				$helper->selectSessionsTable($query);
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->andX(
 					$query->expr()->eq('s.session_id', $query->createNamedParameter($sessionId)),
 					$query->expr()->eq('a.id', 's.attendee_id')
 				));
 			} else {
+				$helper->selectSessionsTable($query); // FIXME PROBLEM
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->eq('a.id', 's.attendee_id'));
 			}
 		}
@@ -494,7 +495,7 @@ public function getParticipantByPin(string $pin): Participant {
 		$helper = new SelectHelper();
 		$helper->selectAttendeesTable($query);
 		$query->from('talk_attendees', 'a')
-			->andWhere($query->expr()->eq('a.pin', $query->createNamedParameter($pin)))
+			->where($query->expr()->eq('a.pin', $query->createNamedParameter($pin)))
 			->andWhere($query->expr()->eq('a.room_id', $query->createNamedParameter($this->getId())))
 			->setMaxResults(1);
 		$result = $query->execute();
@@ -521,18 +522,20 @@ public function getParticipantByAttendeeId(int $attendeeId, $sessionId = null):
 		$helper = new SelectHelper();
 		$helper->selectAttendeesTable($query);
 		$query->from('talk_attendees', 'a')
-			->andWhere($query->expr()->eq('a.id', $query->createNamedParameter($attendeeId, IQueryBuilder::PARAM_INT)))
+			->where($query->expr()->eq('a.id', $query->createNamedParameter($attendeeId, IQueryBuilder::PARAM_INT)))
 			->andWhere($query->expr()->eq('a.room_id', $query->createNamedParameter($this->getId())))
 			->setMaxResults(1);
 
 		if ($sessionId !== false) {
-			$helper->selectSessionsTable($query);
 			if ($sessionId !== null) {
+				$helper->selectSessionsTable($query);
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->andX(
 					$query->expr()->eq('s.session_id', $query->createNamedParameter($sessionId)),
 					$query->expr()->eq('a.id', 's.attendee_id')
 				));
 			} else {
+				$helper->selectSessionsTableMax($query);
+				$query->groupBy('a.id');
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->eq('a.id', 's.attendee_id'));
 			}
 		}
@@ -564,7 +567,7 @@ public function getParticipantByActor(string $actorType, string $actorId, $sessi
 
 		$query = $this->db->getQueryBuilder();
 		$helper = new SelectHelper();
-		$helper->selectSessionsTable($query);
+		$helper->selectAttendeesTable($query);
 		$query->from('talk_attendees', 'a')
 			->andWhere($query->expr()->eq('a.actor_type', $query->createNamedParameter($actorType)))
 			->andWhere($query->expr()->eq('a.actor_id', $query->createNamedParameter($actorId)))
@@ -572,13 +575,15 @@ public function getParticipantByActor(string $actorType, string $actorId, $sessi
 			->setMaxResults(1);
 
 		if ($sessionId !== false) {
-			$helper->selectSessionsTable($query);
 			if ($sessionId !== null) {
+				$helper->selectSessionsTable($query);
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->andX(
 					$query->expr()->eq('s.session_id', $query->createNamedParameter($sessionId)),
 					$query->expr()->eq('a.id', 's.attendee_id')
 				));
 			} else {
+				$helper->selectSessionsTableMax($query);
+				$query->groupBy('a.id');
 				$query->leftJoin('a', 'talk_sessions', 's', $query->expr()->eq('a.id', 's.attendee_id'));
 			}
 		}
diff --git a/lib/Service/ParticipantService.php b/lib/Service/ParticipantService.php
index db91478519c..2995b6f647a 100644
--- a/lib/Service/ParticipantService.php
+++ b/lib/Service/ParticipantService.php
@@ -583,10 +583,9 @@ public function getLastCommonReadChatMessageForMultipleRooms(array $roomIds): ar
 
 	/**
 	 * @param Room $room
-	 * @param bool $loadSession Loads a random session if possible for the users
 	 * @return Participant[]
 	 */
-	public function getParticipantsForRoom(Room $room, bool $loadSession = false): array {
+	public function getParticipantsForRoom(Room $room): array {
 		$query = $this->connection->getQueryBuilder();
 
 		$helper = new SelectHelper();
@@ -594,13 +593,30 @@ public function getParticipantsForRoom(Room $room, bool $loadSession = false): a
 		$query->from('talk_attendees', 'a')
 			->where($query->expr()->eq('a.room_id', $query->createNamedParameter($room->getId(), IQueryBuilder::PARAM_INT)));
 
-		if ($loadSession) {
-			$helper->selectSessionsTable($query);
-			$query->leftJoin(
+		return $this->getParticipantsFromQuery($query, $room);
+	}
+
+	/**
+	 * Get all sessions and attendees without a session for the room
+	 *
+	 * This will return multiple items for the same attendee if the attendee
+	 * has multiple sessions in the room.
+	 *
+	 * @param Room $room
+	 * @return Participant[]
+	 */
+	public function getSessionsAndParticipantsForRoom(Room $room): array {
+		$query = $this->connection->getQueryBuilder();
+
+		$helper = new SelectHelper();
+		$helper->selectAttendeesTable($query);
+		$helper->selectSessionsTable($query);
+		$query->from('talk_attendees', 'a')
+			->leftJoin(
 				'a', 'talk_sessions', 's',
 				$query->expr()->eq('s.attendee_id', 'a.id')
-			);
-		}
+			)
+			->where($query->expr()->eq('a.room_id', $query->createNamedParameter($room->getId(), IQueryBuilder::PARAM_INT)));
 
 		return $this->getParticipantsFromQuery($query, $room);
 	}
@@ -622,7 +638,7 @@ public function getParticipantsForAllSessions(Room $room, int $maxAge = 0): arra
 				$query->expr()->eq('s.attendee_id', 'a.id')
 			)
 			->where($query->expr()->eq('a.room_id', $query->createNamedParameter($room->getId(), IQueryBuilder::PARAM_INT)))
-			->andWhere($query->expr()->isNotNull('s.id'));
+			->andWhere($query->expr()->isNotNull('a.id'));
 
 		if ($maxAge > 0) {
 			$query->andWhere($query->expr()->gt('s.last_ping', $query->createNamedParameter($maxAge, IQueryBuilder::PARAM_INT)));
@@ -667,7 +683,7 @@ public function getParticipantsByNotificationLevel(Room $room, int $notification
 
 		$helper = new SelectHelper();
 		$helper->selectAttendeesTable($query);
-		$helper->selectSessionsTable($query);
+		$helper->selectSessionsTableMax($query);
 		$query->from('talk_attendees', 'a')
 			// Currently we only care if the user has a session at all, so we can select any: #ThisIsFine
 			->leftJoin(
@@ -675,7 +691,8 @@ public function getParticipantsByNotificationLevel(Room $room, int $notification
 				$query->expr()->eq('s.attendee_id', 'a.id')
 			)
 			->where($query->expr()->eq('a.room_id', $query->createNamedParameter($room->getId(), IQueryBuilder::PARAM_INT)))
-			->andWhere($query->expr()->eq('a.notification_level', $query->createNamedParameter($notificationLevel, IQueryBuilder::PARAM_INT)));
+			->andWhere($query->expr()->eq('a.notification_level', $query->createNamedParameter($notificationLevel, IQueryBuilder::PARAM_INT)))
+			->groupBy('a.id');
 
 		return $this->getParticipantsFromQuery($query, $room);
 	}