If a Modal enabled button is parented into a Frame with Visible set to False alongside a UiListElement, shift lock will not work.
This bug does NOT reproduce in studio, only in the game client.
Game link with reproduction: https://www.roblox.com/games/129223711847765/Modal-Bug-Test
Seems this might’ve been some A/B test, because the bug suddenly stopped occurring in every game that it effected for me.
Salutations!
I tried reproducing this issue using the experience you’ve attached, but could not get it to repro.
It seems like it stopped happening on your end, too.
I’ll close the topic for now, but if it reappears again, please send a log and a video of it, and I’ll reopen it.
If you need assistance or info on how to get them, please refer to the How to post a Bug Report - Bug Reports - Developer Forum | Roblox
Thanks for understanding!
Have A Nice Day!