The 90006 errors have essentially made me unable to play since the release of the 24 man raid. I can't stay logged in long enough to clear; I think I've only cleared once, maybe twice. Through all the research and traceroutes and pathpings I've done, only using a VPN has allowed me to play without disconnects. Unfortunately I cannot justify paying for an additional service to play the game, so I've just had to step away from XIV. It sucks because I just reupped for a year, but such is life.
If you really want to play, VPNs will work (there's a bad node in San Fransisco that just eats connection) to bypass the problem points.