I've had 11 Errors 90006 over the last 72h. I'm in the EU (France), I play on PS4. It rarely happened to me before.

Interesting fact: due to my job I have two physically distinct ADSL lines at home, one being with Orange and the other one with OVH (a French ISP who provides solutions for business internet needs).

I've tried to connect to FFXIV with both of them over the past 3 days and I obtained Errors 90006 on both. I've also checked my cables, switchs etc.

Also I have no Internet issue with other online activities. It looks like a 100% FFXIV connexion interruption to me.