Running Mojave 10.14.6 on Mac mini 2018 and MacBook Pro 13 early 2015.
I have tried unticking Safari in System Preferences | iCloud, then re-ticking. Unticking, rebooting and re-ticking and rebooting but the tabs don't come back.
Previously I saw the tabs from all my other devices, e.g. on MB Pro I could see Mac mini, iPad and iPhone tabs.
- On my MB Pro I can see my Mac mini tabs;
- On my Mac mini I see no tabs at all;
- On my iPad I see all the tabs (MB Pro, Mac mini, iPhone) just as before
- On my iPhone I see all the tabs (MB Pro, Mac mini, iPad) just as before.
Of course I would just discover this issue just when I most needed this feature to meet a deadline. Now have to somehow get 40+ web pages up on my Mac mini that were previously only a click away. Very annoying!