Seems like your theory is holding up.

I turned down the nozzle temp. from 200 to 185, and maxed out the fan speed.

The tube was cut back to remove the expanded portion and restore the "lubricated" characteristics of the PTFE material.

So far we're 2 hours into the print. It's not perfect, but it's the first time making it this far without jamming.

I'll have to buy a new tube, and invest in better fittings, as well as a new bed cover.

Thank you all for the tips.