Starting around Monday night I noticed a new bug in the most recent version of Roblox Studio where any Frame object that started parented to a LocalScript when the place file was opened will not render when parented to another Frame. The only way you can get it to render would be to add/remove a child (of any type, excluding BillBoardGUIs, possibly more) from/to ANY UI element in the ScreenGui that holds the setup, not exclusive to the Frame you parented the original problematic Frame to.
Once you’ve corrected it via the method described above, re-parenting it to other frames will work as intended. However if you try and move it back into the LocalScript it started out in, it will act as though you never moved it from the last Frame it was parented to. You can correct this again via the described method above.
Interestingly enough, if you change it’s parent via Undo and Redo (Ctrl+Z, Ctrl+Y), the bug persists just as if you had changed it’s parent by dragging it around. Opening a new place file and following the setup described above produces the same results. I even talked to @Flubberlutsch and he tested it as well, and was able to reproduce it. Also we both tried changing the Z Index of the problematic Frame, but to no avail. If the problematic Frame is re-parented in-game via a LocalScript, it works as it normally would as well, making this only a Studio issue.
My graphics card is a GTX 1050 SC, and Flubberlutsch’s is a MSI GTX 960.
This is a video demonstrating the bug.
Also shoutout to my boy Flubb for helping me discover some of the details of this bug!