Yellowshark, thanks for clarifying. Yes, once I realized retraction was grinding the filament I went back and loosened the extruder to the original factory setting best I could. My last print with the reduced retraction settings made it much further along before grinding.
I saw another post where it mentioned that lots of retraction over time will allow heat to build up in the colder part of the hot end and the filament can soften causing extra resistance, and subsequent grinding. This does not appear to be the issue with the OP's extruder, but possibly mine. Guess the final test will be to completely disable retraction and see what happens.
Thanks for your help.