wifi channel

Level 2
whats the best channel for 5g wifi internet my 2.4 is on auto and 20 mhz my 5g was on 161 by 40 hmz but sometimes when i want to connect to the 5g wifi it doesnt connect until i change the wifi channel to auto or any channel , what do u recommend to put my 5g channel on should i leave it on 161 or auto or diffenet channels