Just a warning to anyone running Tomb on mythic, the encounter bugs if you kill the main boss and don’t kill the boss in the spirit realm. My group nuked the main boss and jumped off the edge and no one was able to release, ended up disbanding the group and the instance is still in combat 20 minutes later.
Link to post with a picture of us all dead unable to release.
https://www.reddit.com/r/wow/comments/goxzdt/mythic_desolate_host_bug/