ISBAT edit captions of images in a Full Scroll Carousel

[cuemarie]

Describe the bug:

ISBAT edit the captions of each image added to a "Full Scroll" type carousel, but I cannot because only the first image added to the Gallery is editable.

To reproduce:

1. Add a Carousel block
2. Select images from the media library
3. Try navigating to other images in the carousel besides the first image - using the chevron sliders, dots at the bottom, or thumbnails (enabled in Block Settings)
4. See that no other images are selectable in the carousel.
   • It is possible to edit the images within the media gallery selection screen, but this only updates the caption for the image in the Media Library and not the live site.

With Gutenberg inactive, I still am unable to edit the captions, though I can advance through the carousel's images.

Expected behavior:

ISBAT select each image in the editor and edit it's caption.

Screenshots:

With Gutenberg 16.3.0 active:

Screen.Capture.on.2023-07-27.at.12-10-31.mp4

With Gutenberg inactive:

Screen.Capture.on.2023-07-27.at.12-16-30-comp.mp4

Isolating the problem:

• This bug happens with no other plugins activated
• This bug happens with a default WordPress theme active
• This bug happens without the Gutenberg plugin active
• I can reproduce this bug consistently using the steps above

WordPress version:

WP 6.2.2.

Gutenberg version:

Gutenberg 16.3.0, 16.2.1, and previous versions, as well as with the plugin inactive.

Originally reported here: Automattic/wp-calypso#71502