Players fall from the lobby the moment they join the game.

This issue resembles a problem I encountered previously with Gun Game or Arena modes: the moment I join, I fall through the floor instead of remaining in the lobby.
If the game starts in this state, I get stuck in a loop of repeatedly dying and respawning,
causing the screen to flicker (an endless cycle of death → respawn → death).
Please look into this.

I tried resetting the center coordinates, but that did not resolve the issue.