I can't play with keyboard and mouse

Whenever I press a input on my keyboard or if I click with my mouse the entire game freezes and locks up for a few seconds but I can look around fine. I know it’s not a hardware issue because I can play perfectly fine with a controller and I am being forced to use a controller if I want to play.

I have the same issue and have no idea how to fix it. I love that i can finally play Halo on PC but would love to get why im forced to use a controller? literally unplayable on my pc with the freezing with ANY button press. PLEASE FIX.

the worst thing microsoft did was give halo to 343 i cant even play this crap