So I have a weird issue. On my iPhone, Safari says I have a YouTube tab open on my Mac (Big Sur). I have swiped to close it many times, but it always comes back. I’ve checked my Mac, and nothing shows up. I’ve even Force Quit Safari.
Maybe toggle off Safari iCloud sync on your mac for a while (30 minutes?) and then turn it back on to force update the Safari iCloud state for your Mac?
Most problems I've had with iCloud have been fixed by some equivalent of turning it off and on again. Such is the downside of making everything "magic" by hiding away all of the controls and presenting only a single button. When things go wrong there's practically no way to debug.
Maybe toggle off Safari iCloud sync on your mac for a while (30 minutes?) and then turn it back on to force update the Safari iCloud state for your Mac?
Most problems I've had with iCloud have been fixed by some equivalent of turning it off and on again. Such is the downside of making everything "magic" by hiding away all of the controls and presenting only a single button. When things go wrong there's practically no way to debug.