Can't solve it blindly, but a few things I can think of:
• when changing the folding settings, it will not change open files, so you need to re-open file (works for me)/restart IDE (surely works)
•
folding regions might be remembered per file, so it only takes effect on unopened files? try manually expanding and re-open/restarting
• I remember seeing "..." previews in the context of
this bug, see repro code comments in `#1`/screenshots in
#2
. Try to upgrade to latest AS (Hedgehog) + AGP 8.2 in build.gradle files. (I see previews in HH + AGP 8.1.x, see attached, and toggling the setting works after re-opening the file.)
If neither of these work, report a new bug at
https://issuetracker.google.com/