confirmed: Battlemaster/Vendor/Banker lag are all related to the same double-click bug.

Like if you are at a bank and it says "you are too far away from a bank" when you try and withdraw, thats because of double click.

If a Battlemaster doesnt queue you when you hit join battle, it's because of double click.

If you try and train skills and it doesn't do anything, it's because you double clicked it.

Hehe this problem was so frustrating to me, i didnt even notice that when it didnt work it was cause of me click-mashing. Kinda funny how you can sometimes do things without even noticing.