Vivofit fails to complete pairing with smartphone

My vivofit (not vivofit 2) is recognized by the Connect App, will begin pairing, but then fails to pair. After that, it is no longer recognized after repeated attempts.

Yes, my bluetooth is on (otherwise it wouldn’t have recognized it in the first place). The watch is literally laying on top of my phone, so they are close enough.

It worked fine before I changed phones. Now, the app is there, the watch is the same, but it doesn’t work.