Air con not operating properly

The passenger side on auto and individual excellent driver side meduim on auto seems cooling and heating on at the same time when switch to individual then cooling is 100% the other side 100% fine did sent for check dealer say I have to replace all the solenoids but again my question why working when switch to individual the gas levels OK pump working fine

another thing is that both air outlets on top of the dash on far left and far right only heating no cooling affect and underneath driver seat only hot air at all times please advise I don't want to strip the vehicle unnecessary

thanks
Willem