Friend can't join our chat and no one can join hers

[aslucc]

There are 4 of us, 3 are able to join the link of each other. We are using YouTube.
The other one has Vemos installed, can create a chat but when we try to join it says she's disconnected (but she is still on, we facetimed while she did it). If I try to join with the code it simply close the "manually connect" pop up and does nothing.
Same, when I create the link she gets the disconnected error when she tries to join but I am online, same with the "manually connect" code. Her Chrome is updated.
What could it be?