Keybinds with key modifiers press the key too?

I’m not entirely sure how to describe what’s happening so here’s a practical example:

I play Guild Wars 2 and have keybinds that use modifiers, for example, shift + F, or ctrl + space. What’s happening is that a lot of the time (not always!) whenever I press, say, shift + E, the game will receive the keypress of the combination but also just E on its own. That makes it so I activate both my pet special skill (shift + E) and my healing skill (E).

This happens for all my combinations so far, but it didn’t use to until I got a new CPU and Motherboard. Google isn’t being helpful, probably because I have no idea what to search, really.

Here’s inxi -Fxz: