If any Diablo 4 players run into this problem, their best bet is to open the map, click on the dungeon's entrance, and choose to leave. They should then be able to re-enter the dungeon and complete it like normal, barring any other unforeseen issues. This isn't totally ideal as it means walking back through the dungeon, some of Diablo 4 Items which can be fairly large, but it's better than...