Allow Apple Watch to unlock my iMac keeps failing

Hello everyone,

This function to unlock iMac with proximity of my Apple Watch keeps failing so many times already that I'm becoming such hopeless about this feature.

I'm able to repair it with just simply turning feature of in macOS, restarting everything, my iMac, iPhone and Apple Watch, then turn unlocking feature on and it works.

Problem is that sometime after few hours, sometime after a day or so, unlocking stops working and have to do all the procedure above over again to make it work. That is so anoynig!

I share my iMac with my wife, it only leads me to a question... Does this unlocking feature suppose to work with multiple user accounts on one Mac and possibly switch between them? Sometime it seems it works, but sometime it looks like logging out and in with different user account brakes this feature.

Does anyone experiencing same problems? Anybody found maybe solution to this??? Thanks in advance for any help, have good evening everyone, bye.

Manoli

My Configuration:

iMac (Retina 5K, 27-inch, Late 2015)

iPhone 8

Apple Watch Series 3

(Latest versions of all OS installed with all available updates.)