This is caused because of the misinterpretation of how OnRoomListUpdate is handled with Photon. It is not a list of all the current rooms, it is a list of the updated rooms. Therefore, when we destroy all the other room list itemss before handling the new rooms, we are actually destroying all the room list itemss which have not been changed.
The temporary fix is pinned on the discord server, and you can find a solution by SFDarkHZ here:
https://discord.com/channels/542907143779516476/731248980310360194/745761364915519569