I'm not sure what the actual issue is. If I try to DM someone I was already connected to, from the corrupted web UI on my new laptop, then the UI acts as a fresh Invite DM. But does not show up to that person.
If on my old laptop with rooms intact, I DM that person my new laptop shows the notication and the room is now listed, shows msg + history.
But when typing in corrupted UI the other person doesn't see it, and on my old laptop warning shield "Unencrypted" shows.