Been having this issue for quite a while... anyone else?

Every few prints, I run into an issue wherein the printer executes its start g-code, winding up at the back, right corner as normal, then it starts extruding filament non-stop. I have to hit Abort & start the print process over. Has anyone else ever experienced this?

That seems pretty strange to me. I suppose you already checked the g-code to see if there was an error.

Do you have a filament run out sensor if not add M412 S0 to your start code. If you do have a sensor it may be having intermittent problems. I had to use the command M412 S0 in one of the firmware versions i used because by default the run out sensor was enabled and it would start extruding endlessly without the command.

Just a thought.

Here’s what marlin does if you have the sensor enabled

M412: Enable or disable filament runout detection. When filament sensors are enabled, Marlin will respond to a filament runout by running the configured G-code (usually M600 Filament Change). When filament runout detection is disabled, Marlin will take no action for filament runout.

I do not have a runout sensor. I will try to M412 S0.