HEAVILY DISTORTED PLAYBACK ON ONE TRACK WHILE TRYING TO RECORD ON ANOTHER

Hello All!

Forgive me, as I am very new to this DAW stuff (Day 3 using Audacity). The subject line sums it up. I have recorded a guitar track that sounds crystal clear during regular playback, but once I try to record an accompanying bass line (or anything else) on a second track (while listening to the first guitar track) the guitar track sounds incredibly garbled and distorted to the point that it is impossible to follow along. I then rewind to the beginning, hit play (without recording) and it sounds perfect again. So you know, I have not messed with ANY of Audacity’s default settings. My inputs are not even close to clipping. My sound card and drivers are up to date. My computer has tons of unused memory. I have tried routing my interface every different way. I have switched USB cables and port locations. I routinely clean out junk files with CCleaner. I have closed ALL non-pertinent applications. CPU usage is minimal. I have uninstalled and reinstalled Audacity. I have re-recorded and retried everything a dozen times. No matter what I do I keep getting TERRIBLE sounding playback results ONLY when trying to record the 2nd track. I have Googled the heck out of this problem for Audacity, Pro Tools and Cubase and can find nothing useful. I’m sure there’s a simple and counterintuitive explanation that my inexperienced brain has overlooked, but until that is realized, I’m going to lose my mind - PLEASE HELP!

Thank You.

FIXED IT, I THINK…**
It had to do with default “Audio Host” being set to “MME” (a 30 year old interface). Switched it to Windows DirectSound and the problem has disappeared!!! I tried switching to WASAPI, since from what I understand, it’s the most current and has the lowest latency for multi-track recording, but each time I tried recording I receive an error message. I’ll be working on this next, but for right now YIPPIE!!! Now all I have to do is re-grow the hair I’ve pulled out… Peace!

NOPE!!! DIDN’T FIX IT!!!
It just made my track#1 (guitar track) sound good while recording the 2nd track (bass track). Thought it was fixed, but then during playback NOW the new bass track is the one all garbled up!
AAAAAAARRRRRRRRRRRRGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG!!! WTF???