Out of sync audio

Ok this happens several times a day. My audio goe out of whack with the picture. I have to go into optic settings and go down to television then screen ratio and toggle from 4K and 1080. Then it syncs. I have a Lg  OLED65CXPUA and a 4 k optik Telus box, we have two other boxes hooked up to other TVs and none of them do this. It’s driving me crazy. Have tried different cords, so it’s not that,. Would appreciate any help, box also has been reset.