Well its finally happening on both Macs. Both running Mojave. Safari bookmarks refuses to sync with my other iMac that is on Monterey, iPad 15.5, iPhone 15.5. Tried turning off Safari iCloud sync on both Mojave Macs for a few min, then turned it back on and still no sync. Ran safe mode on both Mojave Mac and no sync. Turned off Firewall on both Macs. Cleared Safari and held shift key booting Safari. Tried also Safe Mode on both Mac. Safari bookmarks for iCloud just won't sync anymore on the two Macs running Mojave. On my MBA on Mojave, I reformatted the HD, completely removed everything. Tried to net boot "opt, cmd, r" but it won't install Mojave from Apple servers it wants to install Monterey and that's the right behavior with that command. I could try "shift, opt, cmd, r" and try and install what shipped with it. Then try and download the version manually. I guess.