Lag issues specifically on my main. Not on my alts

Since June 8th when I disconnected from the game and logged back into constant 90002 errors and 10105 errors, lag spikes to the point that standing around in safe zones would lag me out. I have been running a VPN since then, which seemed to have worked despite trying every single thing I can think of including calling my ISP because the game was unplayable.

Long story short, I was experiencing some issues last night with sound skipping like I was running the game off a scratched disc and some other graphical freezes. I decided to open my rig and reseat my RAM, etc. I logged into an alt to avoid getting spammed about if my machine was okay and oddly enough, without the VPN and logged into my alt; the game is running flawless. My connection was perfect.

I log back into my main, and it's back to disconnecting and seeing the dc symbol, input lag etc. At this point I have uninstalled my VPN and I've been playing on my alt in the same areas I would lag out on my main. Absolutely no lag at all.

I really don't understand why a connection issue would affect one single character on my account like that, and I'd like to resolve it somehow.

Update: decided to try and backup my settings and then restore them, fixed nothing. I tried even removing all the character folders entirely, no saved configs, nothing...and I'm still lagging specifically on my main character.

I might even try a fresh install, but at this point I kind of feel like that isn't going to change anything.

Uninstalled, deleted everything. Reinstalled, let the game patch over night...and....nothing. still getting the same type of lag and disconnect symbol and input lag on my main even before I restored my UI, Macros, etc.

Seriously considering abandoning my main character since I can't really play it.

Tech support with ISP is worthless, logged into my router and cloned my PC's MAC. I can now play my main without any issues. If anyone else is experiencing this I hope this works for you too.