Comm frequency changes on its own

I have recently started to notice the comm 1 frequency randomly changes to a local frequency on its own. This makes flying on VATSIM almost impossible. I have checked the forums, turned off the AI, checked key bindings etc. but just cannot find a fix.

Has anyone else experienced this and managed to fix it please?

Forgot to say, sometime i notice a pushback instruction without using in-game ATC or using AI assistance?