This is still reproducible in Nightly 132.0a1 (2024-09-21) (64-bit). Here's a screenshot showing the (very brief) intermediate state, from a screencast that I just captured locally. As shown here, the issue (in this case at least) was that the buttons have no text inside of them, which means their height collapses.
Bug 1737785 Comment 6 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
This is still reproducible in Nightly 132.0a1 (2024-09-21) (64-bit). Here's a screenshot showing the (very brief) intermediate state, from a screencast that I just captured locally. As shown here, the issue (in this case at least) was that the buttons have no text inside of them, which means their height collapses. Also, the "Use a custom image..." text is missing here.