"strange bzzz" sound when i play

ok,
here a bug i have only on phoenix point and no others games (like xcom)
When i 'm on a mission or the planet map, I have under the main sound a “bzzzzz” very noisy!

I have an external soundcard “home studio” in 44.1hz. I tried to find the bug, but don’t have any luck. I hope to find help, and maybe, help you to correct this bug

Try turning down or off different sounds in the options to see if you find the one that may be causing the buzz.