Universal Clipboard (Handoff, Continuity) not working, endless spinning in iCloud Notes (Mojave)

 Recently I've had two issues:

1. Mojave Universal Clipboard stopped working between Mojave and iOS 15.4.1
2. Mojave notes iCloud synced but always showed a spinning activity icon

I found that I could make Universal Clipboard work again by creating or editing a note on my iPhone or on Mojave. Once that synced then UC worked until I rebooted.

I may have had success by:

1. Changing my Mojave location DNS settings from Cloudflare (1.1.1.1) to Google (8.8.8.8). (Based on this post)
2. Toggling Notes iCloud off then on again (restores notes)

Now the spinning is gone, and UC seems to be working.

Update 5/15/2022: UC is back to not working unless I create a note that's synced between iOS and Mojave. Notes doesn't show the skinny activity icon. So this is an open problem.