When an element controlled by a UIListLayout is being clipped by a GUI with ClipsDescendants enabled(ex: when the object is outside the perimeter of a frame), that element will be invisible once it re-enters the viewing area.
This seems to only happen with objects controlled by UIListLayout objects, as I’ve created an identical GUI that used traditional positioning, and it didn’t suffer from the same problems.
A video demonstrating the problem:
And of course, the repro place: