Versa 2 won't pair to Revvi 6

[Moxamama]

I recently had to get a new phone, and the Fitbit app transferred and continued syncing no problem. When I was having trouble getting my wireless headphones to pair, I unpaired all devices and re-started my phone before trying again. The headphones paired up right away, but now my Versa 2 will not pair. I've tried all the steps listed on the help page and those found through a google search. I contacted chat support, who led me through all the same steps with no luck. I've tried pairing through the Fitbit app, through my phone's bluetooth settings, and through the device itself, and nothing is working. I don't know what else to do. The watch itself is working the same as usual; it's just pairing or syncing.

Moderator Edit: Clarified subject

[Moxamama]

Update: I have no idea what just happened, but after all of those unsuccessful attempts it just magically synced on its own. If anyone has any idea what the issue was, I'd still be curious to know.

[Moxamama]

And now it's doing the same thing again. Anyone know how to fix it? The official support chat was no help whatsoever, just took me through the same steps I'd already tried after reading the help pages and then offered me a coupon code to buy a new device. But it's working fine, just won't pair to the new phone.