Keychain Access problem - High Sierra 10.13.3 (SU)

Hello to the whole Community,

I've seen a lot of topics about keychain problems, but still haven't found an answer.

In short...

I've changed Keychain Access password (login) and all was OK.

Problems begun a few hours later when I’d restarted Mac.

1. "login" Keychain Settings were reset

2. New password resets to the old one

3. All Safari extensions had been gone

And on the top of all that, most of passwords (apps, mail etc) had to be entered - again.

Is there any solution for this nuisance?