51900319 error ONLY for certain characters

I get disconnected and get the 51900319 error message exactly two seconds after logging into either of two certain characters. It ONLY happens with those two. I can log into other characters and play just fine. I’m a recently returned player from way back which I only mention because maybe that has something to do with the error. A conflict of some kind? IDK. I don’t have any mods or anything like that, it’s a vanilla install.

At this point I’ve done all these steps:
Scan and Repair
Deleted the WTF, Cashe, and Interface files
Switched to a wired connection
Restarted the router (several times)
Restarted the computer (after each change)
Reinstalled the client
Reinstalled the game
Tried enabling IPv6

Why is this happening? What else can I do?

I would start with resetting your password it can reset the server side cache.

I had to reset my password when I initially installed the game. Would resetting it again make a difference?

It might. It can’t hurt. I would also try the unstuck feature sometimes just moving the characters via the system can reset things

The unstuck feature is the first thing I’ve tried. And before anyone else says it yes I’ve tried it again since. Still doesn’t work. I even wait overnight before trying to log onto the character again.