Hello.
1) navigate to group (not sure is it necessary to do it in group exactly)
2) use timeline and upload video (not sure is it necessary to upload files. didn't taste it with embeds videos)
3) edit Description field
4) post it
Result 1: Everything OK
5) DON'T REFRESH PAGE
6) Upload another video to group's timeline
7) edit Description field (click cursor on it)
Result 2: We can notice that placeholder text in video description field "Enter some description for the video..." is editable like on screenshot.
Expected result: this text should not be editable.

Thanks.