I had all paid relays until this happened then I added a bunch of the free ones back to try to fix the problem. I thought I was put on the blocklist everyone was talking about but it seems my followed just were wiped somehow.
Discussion
That stinks. It's happened to me a few times. I've found that it happens when I switch clients and the two clients don't have the same relays. For example I had to re-add all the relays to nostgram.co. Luckily there is a tool on there to restore.
Will be much better when it doesn't happen and things sync more seamlessly.
It's this thing on the account page in case you need it