No changes to network for about a year.
What had been rock solid for 18 months suddenly went south on patch day.

I'm now disconnected via RST 2-4 times an hour (no lag or freeze.. i've been booted as I take damage in a normal dungeon)

I have since grabbed several more instances of this happening, including a full session pcap from login to RST disconnect if required for diagnostic work.

Latest example running absolutely nothing but FF after applying full connectivity support boilerplate:

15972 523.534874 204.2.229.102 192.168.1.68 TCP 286 55006 → 50083 [PSH, ACK] Seq=2341539 Ack=221873 Win=196736 Len=232
15973 523.541852 192.168.1.68 204.2.229.102 TCP 238 50083 → 55006 [PSH, ACK] Seq=221873 Ack=2341771 Win=262400 Len=184
15974 523.561173 204.2.229.102 192.168.1.68 TCP 190 55006 → 50083 [PSH, ACK] Seq=2341771 Ack=222057 Win=196736 Len=136
15975 523.602176 192.168.1.68 204.2.229.102 TCP 54 50083 → 55006 [ACK] Seq=222057 Ack=2341907 Win=262400 Len=0
15976 523.875019 192.168.1.68 204.2.229.102 TCP 238 50083 → 55006 [PSH, ACK] Seq=222057 Ack=2341907 Win=262400 Len=184
15977 523.896164 204.2.229.102 192.168.1.68 TCP 60 55006 → 50083 [RST] Seq=2341907 Win=0 Len=0
15978 523.900744 192.168.1.68 204.2.229.102 TCP 54 50084 → 55006 [FIN, ACK] Seq=11009 Ack=8770 Win=261376 Len=0