Ps5 Mouse/keyboard conflicts

Hi I'm on ps5 ,mouse and keyboard,  when I try to bind right mouse button to walk and middle mouse to ads , even time I try to walk forward it stutters really fast between ads and walk, even though I cleared it and re mapped ? Am I missing something?  I can't figure out how to make take that bind correctly,  it seems to work occasionally but then starts doing it again ,I don't get it ,how can it be fixed?  Also when prone if I want move forward just a bit , it stands me up ! How do you stop that ?     

        Thanks