I wrote a short paper about a microphone to computer adapter that should be avoided.
https://forum.audacityteam.org/t/devils-adapter/46592/1
It seems like a gift from the angels. A simple, inexpensive cable to adapt your good quality XLR microphone to your computer. Depending on your computer, that will produce the oddly damaged stereo tracks you have.
You can continue to do that little phase process to each new track, or stop using that cable.
Koz