Why then keep a fresh empty instance on an old domain? IPs don't match either, something is fishy.
>i thought it would fuck up federation + following relationships or something
Reasonable concern, though I think if you resend follow request to an user who already accepted it, it should go through fine, at least on Pleroma and in case of non-locked profiles (at the very least it was the case for me when Nekobit moved back and forth between domains).

>(compatible; Pleroma 2.5.50-194-g00ebaee6-ryona-dev)
Huh. I think I've explicitly warned against using my fork for third-parties, but this warning got lost with the rest of kiwigit. There's zero quality control, I merge shit in master branch to test and then fix it as I go on. Expect everything to break if you update it at the wrong time.
If you've gone with it because of custom reacts, consider Eientei's fork instead, Yukkuri maintains a better workflow in that regard.
https://gitlab.eientei.org/eientei/pleroma
https://gitlab.eientei.org/eientei/pleroma-fe

someone I know forked rebased just for his own use and still had people asking him how to run it despite his domain specific modifications.

Was it the furry instance that renamed the repo due to association with ?