I think that Fun realized and fixed it for a few reasons:
1. They are now showing up on the explorer as mining blocks.
2. A while ago the computer I had on the Fun pool stopped getting work from it and failed over to the foundation pool. It is back on the Foundation pool again.
3. The divergent chain appears to have gone away. Meaning my wallet now shows the same as the explorer. That block I mentioned in my last post (279822) now shows a different hash in my wallet than before. It now matches the explorer.
20:19:46
getblockhash 279822
20:19:46
1f54f8930f2335add5b5b673ab50c48b9fe55372031c31ebf19bc8214f6deb4d
Yeah, I think you are right; I think fun was mining on a fork for a few hours (this is based on a discrepancy I found in my graph between 5AM and 8AM).
And apparentely your node was subject to the same fork but it recovered.
On a side note, I was able to pull up the tx that Fun sent to your node while they were on a fork, and it got saved as 'off the main chain' on my node (IE height -1).
I think this has something to do with chainlocks. Chainlocks 'tried' to start 400 blocks ago but as of last night didnt start yet (this is because of the quorum settings which is normal).
I noticed this morning, I didnt see a chainlock yet at the tip. Then a couple hours later I saw some chainlocks 5 blocks behind.
Im starting to think that there were not enough participants in the quorum to lock to the tip.
Right now I see all the blocks locked up to tip -1 (getblock blocknumber) look for chainklock:true.
So far all Ive found is one of my servers (server 6) is not synced; so let me resync those nodes now and then I will continue to look at this.
Im making the early assumption that our network shifted over from RX only consensus to RX + Chainlocks this morning and we experienced a 'large hump', but thats all I know so far.

8100 BBP