Hi Albert, Thanks for your reply. I’ve uploaded a sample project here. Additionally, here are screenshots with Liquid Glass enabled and disabled respectively. Only when Liquid Glass is disabled does the popover background color appear:

Thanks Albert. I’ve filed FB20714325

Hi Albert, Looks like this has improved in 26.1 beta 4! I’m no longer able to reproduce the glitch on every push. There’s still some weirdness where after resizing the sidebar, the next push still causes the back button to reposition itself, but it’s better than before. I noticed the status of the bug I filed is “Investigation complete - Unable to diagnose with current information”. I included a screen recording and sample project. Was there anything else I needed to include?