Device: Switch
Map: Shambali Monastery
Mode: unranked escort (has happened both defense and both attack)
It was only visible for me as my sister playing with me was not seeing the bug on her game.
I have encountered this bug twice on different days. The first time it was not very bad, kinda pretty. The second time i could not see at all.
On the Shambali Monastery map, textures were bugged, they became rainbow and glowing.
The first encounter it was only chunks, the second time it covered roughly 90% of the map.
I have pictures of the bug if needed