macOS, Safari 15, iCloud tabs are missing

Hey,

I noticed that iCloud tabs are missing in Safari after I've updated it to 15 version.

This happens only on Macbook. iPhone and iPad tabs and tab groups are perfectly in sync.

There's even no option in Safari on macOS to turn iCloud tabs in preferences button on start page:

I tried to turn off and on Safari in iCloud preferences both on macbook and iphone. Still no luck.

Any help would be highly appreciated.