Updated to 4.01 on PS4 this morning (GMT) and have been unable to stay logged at all.
Constantly disconnecting as soon as I join the server, kicked within seconds if I am doing actions, up to 5 minutes of watching everyone else run around if not. EU player. Main on Diabolos.
Can log in and play on alt on Sargatanas, including zoning.
Can log in on main using Mobile Hotspot data on smartphone.

Sent Support Desk ticket hours ago but no reply yet. Almost 2am so heading to bed lol.