when im in game i cant cast any spells

this bug used to happen to me like once in 100 games so it didn't bother me bc all i would need to do is just restart the game and it would fix it self. but during my only 2 games today this bug occurred and the usual fix did not work. does anyone know how to fix this? at this point the only way i have found around it is to rebind them to mouse buttons but that comes with its own problems.