Audio missed through display port cable.

Maybe problem is simple but I have no audio on monitor with speakers connected with mini display port to display port cable. I checked several different cables and with each is the some. Strange is as setting for display doesn’t work and BB AI-64 doesn’t recognize display type, shows only resolution 1920x1080 with some star and no frequency information… When I do things with Asus Tinker Board there are settings for display audio and all is working excellent. System is factory installed but when I do boot from micro SD cart with latest available image is the some. If somebody has solution please let me know without not necessary discussion. I want try this board in meantime between microcontrollers boards from Microchip to give some inspiration for my grandchildren (I am 72). Heating is another problem for BB AI-64 with radiator bottom but with two small fans and maybe reverse position it should be not so hot what is not proper.