I'm a long-time v6 user but suddenly 80% through a reel of PETG filament I have started to experience filament "bulging" which causes extruder skipping about 20-30 min into a print. Here's a picture of what I pull out when this happens: You can see the dark area and subsequent bulge which I know is not normal. I have never had this type of issue with an E3D hotend before so I'm mystified why all of a sudden its happening. Everything is stock E3D 1.75 hotend, I have PTFE tube in place. It is cut flush at the top of the hotend. Using .5mm retraction so that's not the issue (which I read can cause this). Fan is stock E3D, I disabled my print bed fan as well and this still happens. Am I correct that the bulge is heat creep and that's where my jam is? Any recommendations on what to adjust?