Filmstrip components sometimes only re-render if the user moves their mouse pointer

As I’m using a modified version of jitsi, this is probably not a bug of jitsi itself, but maybe someone can point me in the right direction to fix it anyway.
Sometimes if a user joins or leaves, the filmstrip doesn’t seem to recognize the state change and won’t update the UI. Only when I interact with the UI somehow, or just move the mouse, the tiles update.

Any ideas or tips on how to debug this problem?

You may try to reproduce the same issue on meet.jit.si to be sure if this is related in Jitsi or in your setup.