You know VLC Player has a repair option. You might try it on one of the songs just to see what happens, other then that not so sure how to proceed.
I took your suggestion about the VLC Player and was about to try it when I went to one of the MP3 files that has been affected only to find it was playing just fine. I checked other offending songs and they too were good. That really has me beat that after months of the problem, fixed.
One thing I did do before coming here was download Malwarebytes 3.5.1 and ran that it, It found the following:
Registry Key: 3
PUP.Optional.DriverPack, HKU\S-1-5-21-3408900908-3900527789-1759740724-1000\SOFTWARE\DRPSU, Quarantined, , ,1.0.11622
PUP.Optional.DriverPack, HKLM\SOFTWARE\DRPSU, Quarantined, , ,1.0.11622
PUP.Optional.DriverPack, HKU\S-1-5-21-3408900908-3900527789-1759740724-1000\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\INTERNET SETTINGS\ZONEMAP\DOMAINS\drp.su, Quarantined, , ,1.0.11622
Registry Value: 2
PUP.Optional.DriverPack, HKU\S-1-5-21-3408900908-3900527789-1759740724-1000\SOFTWARE\DRPSU|CLIENTID, Quarantined, , ,1.0.11622
PUP.Optional.DriverPack, HKLM\SOFTWARE\DRPSU|CLIENTID, Quarantined, , ,1.0.11622
Nothing changed regarding the MP3 files afterward so I came here for help. Perhaps there was something quarantined that was doing it but didn't show immediately or it was unrelated, I don't know. Hopefully it's a permanent fix, whatever did it.
Thanks Zep for your suggestion. I learned something about the VLC player I didn't know.