Catalina 10.15.7 (19H524) on z390 Designare back panel audio not working at startup until headphones inserted to the front jack socket then removed

Catalina 10.15.7 (19H524) back panel audio not working at startup until headphones not inserted to the front jack socket.
I.e. if I insert headphones and then select Headphones as output I can hear sound from headphones. If I remove headphones jack then I can hear sound from my dynamics inserted to the back panel but I can't hear anything if I'm not mangling with inserting and then removing headphones.