well as it turns out it was me, not the PETG.
I pulled out the PETG and tried some PLA and it got worse. Then my nozzle loosened up and I had melted PLA everywhere.
I replaced the heat break, heater block, and nozzle, and no more build up with PETG or anything.
I must have had something stuck in the nozzle.
Now I love PETG again.
Thanks everyone - happy printing