An element that’s been edited by me or another user gets locked by the board (not user) and the bounding box with the user name tag appears. There is no way to unlock it manually, only to wait quite a while for it to unfreeze by itself. It looks pretty much like the Dropbox function (they lock the file so you couldn’t edit it until it fully synchronized). But in the Dropbox I can stop syncing and edit the file, while in Miro I can’t do anything.