YouTube not working after updating to Safari 27.0

Today I updated to Safari 27.0, and now YouTube won't work. The page loads, but when I click on a video either nothing happens, or it tries to play the video but never does. I've restarted and cleared cache, but still no luck. I'm using MacOS 15.8 on MacBook Air 2020 (Intel).

Any tips on how to fix this?

I've submitted feedback to Apple.