H60 Pro: other players hear their voice back when microphone is plugged in

[Uff182]

I've been using the H60 Pro headset for a while now, but only recently I started chatting  with some friends of mine and they all reported that they can hear their voice in return when I join the chat (be it Steam voice chat or XBox Game Bar voice chat).

I did different testing, both connecting the headset using jack only to front and rear panel and also using the USB audio card provided in the package, but the result it always the same.

I'm running with:

W11 Pro 22H2
MSI MPG X570 GAMING EDGE WIFI MoBo

I already checked that all the other input devices are turned off. As soon as I plug in a cheap Trust microphone and use it as input source together with the headphone, the "voice in return" problem is solved.
Do you have any suggestion on what I might check?

Thank you.