Lots and lots of lag followed by 90k errors (90002 specifcially)

[Kazgrel]

I am at my wit's end with this. Every day now, for at least since 4.15 came out, I pretty much get a constant barrage of 90k errors. I'll start lagging and get the offline indicator next to my character, then anywhere from 30 seconds to 3 minutes, then boop, 90k.

As I was typing this, I was standing at the mini cactpot guy in GS, with literally no one around...then soon as I clicked on that NPC, I redlined for about 3 minutes but didn't get completely booted and 90k. The issue seems very prevalent whenever I join groups for A/S rank hunts; I'm lucky to get a kill of a single one of those without lagging out nowadays.

Nothing on my end with my PC has changed, nor with my ISP, although I did notice the tracert going from me to the Aether DC IP now goes through Atlanta > Dallas > San Jose, whereas I recall when the NA datacenters first moved, traffic from me was going Atlanta > Ashburn (VA) > Seattle > San Jose. That being said, the only time I've ever seen packet loss on dozens of tracert runs was at the penultimate hop.

Not sure what else to do at this point; I've done the normal stuff, rebooted all the things, etc. The lag is only occurring with this game; I've sunk nearly 100 hours into Diablo 3's season 12 (as a result of the issues when trying to play this game) with zero bouts of lag or disconnects.