My 2 cents and a suspected cause. Disconnects were a constant with me for maybe 2-3 months, just kinda got used to it.
As mentioned above using more than 1 client seems to increase the disconnects but, the one that truly irked me was this...
I logged into an endless journey account last month, purely to get additional BODs as I was going through one of those phases and...
Created new character
Logged on
Disconnected
Logged on
Disconnected
Logged on
Disconnected
Tried to log on...
Banned, use of 3rd party program.
I've used a 3rd party program for decades to make some tasks easier on my 2 main paid accounts yet within 10 minutes of creating a new character on an endless journey account, it's banned.
Here's the kicker, the 3rd party program was being used on my main accounts, not the endless journey.
Absolutely laughable, happy to ban a free account but if its paid? Turn a blind eye.
It's fairly clear to me they have the ability to scan what you are running now which i dont like. Either way, I ended my subscriptions for them, it was as good a reason as any to finally quit and the disconnections were becoming too annoying. So yes, I've banned myself since they were incapable of doing it!
I stopped Pvping when AoS came so I'm not one of those PvP cheats, I used the 3rd party program for quality of life improvements things that should have been features decades ago!
Anyway that's my take on it, take it as you will but I think there is more to the disconnects than meets the eye.