I am getting a red "Cannot read properties of undefined (reading ‘startsWith’)" when I try to move (by renaming) a page (in root folder) into an new or existing folder.
I can rename the page itself if I don't try to move it and all of the Linked Mentions are updated.
Yes, this is a bug that I have since fixed in the :edge builds. You can either switch to that or wait for me to do a patch release (maybe tomorrow or later this week).
The problem only occurs (I think) if you rename a page that has an external link on it.