First track muffles the sound of new recording

Hello!

I am using Windows 10, Audacity 2.1.2, by the installer, NOT the zip.

I have a stereo drum track.
When I try to record a second stereo track using the mocrophone,
the first track is compressing the sound of the recording.

If I sing a steady note, the volume goes down with every beat of the drum - like a compressor.

I have tried all kinds of settings, including the ones recommended in help - to no avail.

MME, WASAPI, Directsound,. it’s all the same.

This is a new pc, there was no problem on the old one.

I hope you can help me -
Best regards,

Knud

Make sure [u]Windows audio “enhancements”[/u] are turned off.