The latest Safari Tech Preview [Release 167 (Safari 16.4, WebKit 18616.1.8.2)] shows problems when a video is paused. Specifically, after a period of about 5-10 seconds, the video shows as white on YouTube (such as https://www.youtube.com/watch?v=6GEWSNylwS8) and reloads or shows reload-related error on other sites.
<rdar://problem/107797759>
We couldn't reproduce with STP 168. Please re-open if this is still happening for you.