no keyboard input after changing resolution ! help pls

hello communtiy

i have following problem.  i am using a gaming notebook that can not handle this game with 1920 x 1080.  when i try to lower the resolution my keyboard dont reacts anymore there is no input possible. 

i can only run it fine at 1920 x 1080  the keyboard only works in that mode ?   Can anyone help me pls how to fix this issue ?  ( i have no gamepad )