Hi New to the forum and am hoping somebody may be able to help me. I have bought a Logitech K810 keyboard to use with my nexus 7 tablet, 2013 model. Some of the function keys are not responding. F4 Application Switch. No response. F7 Play/Pause. Only pauses. F8 Mute. No response. I am puzzled why these keys are not working when all other F keys are ok. Thank you.