YouTube audio always out of sync
iMac (M1)
Ventura 13.4
Safari 16.5
I've been using Apple products for about a decade now and this has never happened before but it's happening all the time now. I got this iMac this summer and it was fine for a few weeks but it's just getting worse. Youtube audio is always WAY ahead of the video. When it started it was only about a second but lately it's been more like 10 or 12 seconds. Clearing cache/cookies/what-have-you makes no improvement. The only thing I have noticed that works is doing a full reboot. A soft reboot (restart) doesn't work. It has to be a hard boot (shut down). The more often I do the hard boot thing the faster it goes out of sync. It used to take several days to become misaligned, then a few hours, now a few videos. I have checked my Safari settings. JavaScript is enabled. There are no extensions. I am not blocking cookies.
Ideas?
iMac 24″, macOS 13.4