Not all thumbnails of media in "all media" view in chat are visible

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

Bug description

After opening chat and viewing all multimedia in this chat, sometimes some of the photos are blank, white areas, but you can view them after touching them. They can be noticed, because there are four images in row and one of these more in center are blank, so the previous and the next ones are correct, visible, and this one is just empty, white box. I noticed that both in chats and in group chats. Every blank area can be opened and full-size photo appears.

That's a bug since a long time.

Steps to reproduce

• go into chat (also in group chats)
• open all media view in this chat
• scroll down, sometimes there's a chance to notice blank area between photo thumbnails (on 6.8.3 scrolling down and then to the top again helps, missing thumbnails are back, but new ones are missing then)

Actual result: sometimes one of the image thumbnails is not visible, it's just a white area
Expected result: all image thumbnails being visible

Screenshots

Start by reproducing the issue in a chat and group chat's all media view, scrolling down and back to the top while observing the thumbnail grid. The fix is complete when every image thumbnail remains visible rather than appearing as a blank white area, while each affected image still opens full-size.