There is no mention of your retraction settings in this or your original post. 3.5mm retraction distance is a good average starting point, perhaps 4mm at max. Any higher than that and you will get clogs, which I suspect is the clogs you had with PETG.

As for switching back to PLA, you probably didn't clean the PETG out of the heatbreak and nozzle. Since this melts at considerably higher temperatures, you have globs of plastic build-up inside there that aren't completely melted at 220 degrees. When going back to PLA, heat it up to PETG temperatures (240) first and push some PLA through until you don't see any more of the PETG color coming out.