Apple Watch unlock issue with multiple profiles

Using multiple user profiles on a single Mac can cause the Apple Watch unlock feature to fail when running macOS Sierra or macOS High Sierra operating systems. This problem is reproducible 100% of the time when using my 13" MacBook Pro w/TouchBar, however the symptoms vary slightly between macOS Sierra and High Sierra as follows;

1. Ensure that your Mac is already configured to allow your Apple Watch to unlock (Preferences/Security & Privacy/General).
2. On either macOS Sierra or High Sierra, log into a different user profile without first logging out of the first profile (i.e. switch user).
3. Switch back to your original profile and check if Apple Watch unlock is still working.

• On macOS Sierra, the system simply never checks for an Apple Watch and therefore the test should fail.
• On macOS High Sierra, the system asks for an administrator password (but it only accepts the profile users password). It never checks for Apple Watch and therefore the test should fail.

The only fix that I have identified for this issue is to Shut Down or Restart the Mac. This restores unlock functionality for the Apple Watch, but only until the next time that multiple users are active. I still seek a more permanent solution.