Static in Second, Third Track Issue

I do podcasts. When I record in the first track, there are no issues. Starting with the second track on, there is static coming through my headphones. On playback, all tracks sound fine. I uninstalled 2.1 and downloaded the latest 2.1.3 version and the issue hasn’t changed. I am hopeful with the help of this forum I can figure out the cause of this, and whether it is related to Audacity, my mixer or my computer.

What is the make and model number of the mixer and how does it connect to the computer?

Have you tried different headphones?