It’s been many months since I last saw iCloud sync tabs correctly between my 18.x iPhone and my Sequoia Mac. And as of yesterday, bookmark syncing has also broke down. New bookmarks I create on Mac don’t show up on iOS Safari and a new bookmark I set up on iPhone Safari refuses to show up on Mac Safari. App relaunches change nothing about any of this.
This just is not be that hard! It’s aggravating Apple cannot figure out cloud. They used to love to talk about how their mobile and desktop platforms were superbly integrated and advertised iCloud for exactly this kind of sync. But now? Broken mess. Ugh.
Edit: And yes, I have tried turning Safari sync on/off in iCloud settings on both the iPhone and Mac. Does not help. Also, I just noticed that Reader sync is also broken in both directions. This to me is unusual. In my past experience, Reader usually worked even when Safari tab, bookmark, or history sync over iCloud was broken.
For decades now (yes since the late 2000s), I have been unable to sync Safari bookmarks using iCloud. When I bring up a new machine, and I forget to uncheck Safari bookmark sync in iCloud settings, I invariably wind up with hundreds of copies of my Safari bookmarks. This has been going on since at least Sierra.
After I forget, I know to go to /Users/username/Library/Safari and erase bookmarks.plist (which has usually ballooned to around 15 MB), which restores the defaults. I then import the real list (a single copy) from an HTML file.
Numerous bug reports filed with Apple have had no effect.
So bookmarks and history have started syncing again. Tab sync is as broken as ever from iPhone to Mac. The Mac OTOH appears to be able to send its open tabs to the iPhone again. For now. Just fix it, Apple. That goes for the lying status page, too.