Mouse5 seems to mess up backspace and my console

Heyo. So, I’ve been having an incredibly strange issue recently, where my Mouse5 button causes my backspace key and console to stop functioning, and mouse5 itself doesn’t work at all. This only started happening about a week ago, and I’m totally at a loss. I’ve tried verifying my game cache, rebinding keys, updating my mouse drivers, and I swapped my new mouse to my old mouse. For the record, I normally have Mouse5 bound to sprint, mouse4 bound to PTT on TeamSpeak, and backspace isn’t bound to anything. My launch parameters are -dxlevel 90 -dev 2 -console, if that makes a difference. New mouse is an Eagletec mouse that came with my K005 keyboard, old mouse is a Logitech G300, but I never had a problem with either before about a week ago. Backspace works on all other programs except Garrysmod when this happens.