[Miller]

Could be caused by the dense tile bug, so wait until the update to see if it still occurs. If it does any information on it would be helpful. (Who's in the battle, what is the battle map terrain theme, etc.)

This only occurs during Black Beast raids(Tannis) and PVP battles as far as I'm aware, I haven't encountered it yet during this update nor do I know the details of the dense tile bug. This can occur with one person during a battle with black beasts(Although the glitch CAN happen with multiple people, but the second person is likely not glitched and can free the spawn point.)

As for PVP, this occurs when someone is occupying a set spawn point(?) and moving away from said spawn point in battle lets the one joining the battle in. Otherwise they have a black screen until they spawn. I believe this occurs on any map, although I haven't seen this occur on anything aside from the standard field(Grass) map.

Edit: You can use the battle hud normally and end turn to 99 rounds to get out of the battle.

Example of what it looks like for the trapped.