Cannot Move Mouse When Holding Side Buttons Remapped by BTT

I don't know if this should go under bug reports. I've noticed a problem with BTT and it is quite a literal game changer for me. I remapped my mouse's side buttons to press number keys. That works, but I realized I can't move my mouse if they are down. My mouse can move, but it doesn't register. For example, if I'm pressing my mouse side button and move my mouse over a link, it doesn't change to a hand icon. In my game, when I move my mouse when the side button is pressed, nothing happens, but as soon as I release the side button, my player very very quickly aims in that direction. That is quite a problem for me, and it sort of looks like I'm using aimbot. If I could quickly press and release the side button, the problem would basically be fixed and I wouldn't be writing this post. The problem is, the game forces you to press that key for a certain duration to prevent macro users.
Has anyone else encountered this problem before?