We understand players have had trouble accessing Minecraft Preview on Xbox today. This will be resolved by an update in a few hours.

Xbox game pass for Minecraft Dungeons always seems to crash

I have it on mine and I'm not having any issues (That doesn't take away that it's happening to you) have you uninstalled the client as of yet? Make sure to save your character first though. ^TK

Not sure i understand what uninstall the client means ??