Expelled for PMs

So this is an issue that I had on the old server which was originally fixed but which has returned. Sometimes (not always), when I a) open my PM inbox b) select a PM or c) send a PM I am randomly signed out. Upon signing back in, I am cordially escorted to the GP homepage and upon returning to my PM inbox my message has been deleted.
I was hoping it was just a one-shot thing that wouldn't happen much or that I'd just be able to suck it up and deal with it, but I'm beginning to loath PMs because I'm looking at having to sign in and go back and draft my message multiple times (copy/paste it elsewhere you say; well, I'm not that smart) before it lets me through and sends it. Thanks!

Wait, the PMs are being deleted? That doesn't make any sense at all. Last time, I never figured it out; it seemed to go away. I'm not sure why it's doing it now either, but I'll dive in...

For a second there I thought someone had been kicked from GP for PMing people... This seems like a particularly nasty issue. Good luck hunting it down Keleth!

Not saying this is what's going on, but on my other, older phone it's impossible to zoom into the header menu. So more than half the time when I tap my avatar and attempt to tap Messages from the dropdown I end up logging out instead! :-P

Hahaha I wish that was the case, but I'm on a laptop and am pretty sure I'm hitting the right button. It also happens when I open a specific PM/send a new one, so I don't think that's it. xD