Audio output leaking into microphone

I noticed that my audio output (anything from system sounds to music) is leaking into my microphone.

Stereo Mix is disabled and the audio is not loud enough to be recorded by the microphone externally, probably it's crosstalk from the wires but I tried with a brand new headset (by the way they're both with 3.5mm jacks) and the problem persists.

I also tried (with both headsets) to connect the microphone and the headphone to different sides (microphone front and headphone rear, and vice versa), but still it leaks audio into the microphone, sometimes even when the microphone is disabled hardware-wise (with the button).

I know that probably there's something wrong with the motherboard' sockets but i noticed that TeamSpeak3 is the only software i know of that isolates audio output and input when selecting the "Windows Audio Session" option, so maybe there's a solution with a software that enables WASAPI for any application.

I'm not trying to record audio, i mainly use my microphone for stream and VoIP (Discord really detect any sound from the output and redirects it into my microphone, i can't listen to something loud without letting the other users listen to the same thing and if i lower the sensitivity they cannot hear me).

The crosstalk problem appears to be an electrical design issue of the "common audio ground" of the mic and speaker jacks. Connecting an amplifier speaker to the headphone jack seem to not cause the crosstalk, its only headphones. The solution is to separate the grounds for the two connectors. I resolved it by running a separate ground wire from the rear pc stereo output jack's sleeve, by looping it around the speaker jack end, to the headphone jack's ground; as suggested in this question: electronics.stackexchange.com/questions/373716/pc-headset-crosstalk

Found a fix for this, right click on speakers on the bottom right Click on sounds Click on playback Right click on every single item displayed and disable it except for the one you are using. Do the same thing for the recording tab. Test.