I have a talent for finding bugs, basically nostrudel has this feature to login as someone else to explore what nostr is like using their profile.
I did this because I didn't discover the blindspot feature yet, I saw someone I liked and wanted to follow so I clicked follow but this didn't go trough as I forgot I had signed in as them. I switched the profile back and followed, but somewhere in the cache it didn't change it to mine yet so when it wrote the updated list all my follows were reset. That NostrFlu tool can display each relays follow list, so you can see which one has an accurate copy and thankfully I had one relay keeping historic versions as well as a relay that was slow at updating. So I was able to rebroadcast the correct follows despite never having made a manual backup.