I just logged back into a Realm about 2hrs after I logged off, only to discover that my inventory & location had been rolled back by about 1hr-1hr 30m.
The owner of the Realm dint restore world from earlier backup, so I'm assuming the server decided to rollback on its own. Not entirely sure what caused this, however here is a screenshot I took before logging off & this incident occurring.
Due to this being a Survival Realm, I know none of the other invitees could've made the crater in the image, so I thought maybe the Realm crashed. To my surprise, I was able to place blocks along the inner part of the hole.