I have been living with some strange gaps in handoff on my Mac for a while now, which I have putting up with in the vain hope that they would be magically fixed when upgrading from 10.11 to 10.13. Sadly, no joy. The issues centre around FaceTime and Messages, and how my Mac integrates with my iPhone. When a text message/iMessage arrives, my iPhone and iPad are updated virtually simultaneously. Messages usually update on my Mac, but often take as long as 10 minutes to propagate. Incoming phone calls similarly trigger immediately on the iPhone and iPad. Sometimes, but not often I will be prompted to answer by my Mac as well. My iPad can initiate outgoing calls no problem. My Mac however, insists that my Mac and iPhone are not on the same Wi-Fi network. This is incorrect. They are on the same Wi-Fi network (both on the 5 GHz network), and Bluetooth is enabled on both. They can see each other on Bluetooth. The fact that incoming phone calls occasionally trigger my Mac proves to me that the wireless infrastructure is correct. It seems to me that this is an issue with authentication/certificates between my Mac and my iPhone. I have done the logout & login to iCloud dance on all devices multiple times, with no change. I have cleared out all of the obvious preferences and certificates from my user directory and keychain — again nil. I have also updated from my iPhone 6 to an iPhone X two weeks ago, and as mentioned above, updated from 10.11 to 10.13 just yesterday. I've tried disconnecting my ethernet and forcing my Mac to use only Wi-Fi, but this makes no difference. I am really out of ideas. This used to work, and worked for ages. Unfortunately, when it stopped working about a month ago, I was in the buildup to the Christmas rush, and really didn't have time to diagnose the issue. Any thoughts, suggestions?
Any help will be apprecited.
I didn't find the right solution from the Internet.