--snip--
I wonder if the spam attack still happens or is it reduced? Been long fees went up that high.
I wonder exactly how that was fixed(assuming it has been fixed). IP ban? Or through some other means?
Well, it's been a long time since the mempool was flooded in such a dramatic way as it was flooded in 2017-2018 (don't remember the exact time period, just that it's been a couple of years). It's possible that the "spammer" is still creating transactions, but if he does, it's no longer to a degree that causes issues with other people.
There is no real way to ip ban spam transactions. Transactions are broadcasted trough the network, nobody knows who created them. Ip's are not recorded on the blockchain, nor are they transmitted together with a transaction. If you really wanted to ban "spam" transactions, you'd have a hard time, since there is no difference between a spam transaction and a "valid" transaction (spam transactions are valid aswell).
You could ban peers you suspect being the source of spam transactions, but all nodes would have to use the same blacklist (and the spammer can just use a different ip to broadcast his spam, so you'd have to update the blacklist every couple of minutes). If one of the nodes wasn't willing to ban the suspect peer, the suspect would still be able to broadcast to the node that didn't use the blacklist, and this node would still relay the spammers transaction unhindered.
A second thing you could try is to convince miners not to include transactions using unspent outputs funding certain address lists, but nobody knows the complete lists of all addresses belonging to the spammer's wallet, nor would the miners be willing to help you (since they're missing out on income if they do this).
Neither of these options is bulletproof or feasible, and all options would depend on incomplete, centralised "blacklists" that would have to be honored by the complete network (all nodes and all miners), and one option would even cost the miners a substantial amount of income, so it's not likely they would be willing not to include valid transactions that have a higher fee per vbyte just because somebody says it's spam.
If we put aside the assumption most people have about who the "culprit" is, and why he/she spammed the network, only a couple possible explanations could be given as to why the attack stopped:
Either the attack was deliberately, and it stopped because the culprit reached his/her goal, made his/her point or ran out of funds
OR
The attack was unintentional, and the "culprit" found out he was the reason why the mempool was filled to the brim (and the fees were out of proportion) and he/she stopped spamming... Or maybe it was unintentional, and the "culprit" just needed several thousand tx's confirmed, and once this was done he was content.