adding a audiotrack: weird behaviour for source

Cool. Thanks. I’m not familiar with that interface, I’m looking it over. Looks nice:

I’d re-check your audio drivers and set-ups. If the mic is going into the Studio 100 and you see meters and can headphone monitor the mic at the Interface, you know you’re good to that point.

Re-check your USB drivers in Device Settings and make sure everthing seems right. I’m not sure which driver is best for you to use.

If there’s a Cubase problem, you may have to re-set the program’s “preferences.” When you say ‘different files’ – are these files you’ve imported into
Cubase?

Input and Ouput assignment in Cubase is very straightfoward and it all should work absent some kind of hardware issue, a bad cable (s), broken mic. There are some issue that show up at times in Cubase when dealing with complex Group Track Settings, but this doesn’t sound like that.

If a certain track preset has some very aggressive settings, it might attenuate the Mic signal to a great degree.

Load the tracks clean without any presets and make sure everything is OK, then add tracks with Track Presets. I hope it gets sorted out without too much trouble.