I have purchased a Casadei K320 edgebander. I have tuned and clean it up, and for the most part it works ok. However, there is a lack of glue on the leading 6mm of the edge being banded and thus the banding is not adhering well on those first 6mm. Specifically, it is the upper and lower corners of the leading edge that aren't adhering well. The rest of the panel is adhering very well!

Here's what I've done: glue pot is COMPLETELY clean and glue is fresh. Guide shoe is set 0.5mm away from the glue roller as per manufacture's suggestion. Glue temp is in the mid range as recommended by Jowat. Pressure rollers are set to be inline with the infeed and outfeed fence. I have tried removing all sources that may be "dragging" the banding as it first contacts the leading edge of the board (edgebanding roll, guide channels, guillotine cutoff, etc) - this does not seem to remedy the issue (I've watched closely and the tape is not pulling the glue back from the edge).

Any thoughts?? I'm at the point where I'm just going to cut my panels 18mm longer than necessary and trim the ends after banding. But that is more work. Any help/insight would be much appreciated.

I would bring the infeed fence closer - .2mm. Also try to see if the fence is parallel to the chain line. This is hard to do because there is no visual reference.

Do you mean the glue roller guide shoe closer (ie: 0.2mm) or the actual machine's infeed fence? Closer as in "increasing the offset of the infeed fence" relative to the rest of the feed line to create clearance for the tape? Right now, the infeed fence is perfectly parallel with the feed line - I wonder if it needs to be offset toward the front of the machine the thickness of the edgetape?

Your infeed fence and glue feed shoe should be in line and .2 mm out from the glue roller. Tape is applied down run from there. The pressure rollers are sprung but should be set for the thickness of the tape. You should not feel any panel engagement with the glue roller and no abrupt bump when the tape and panel hit the pressure rollers but you should see the rollers retract on the spring slightly.
The world is so much better with banders that have sprung glue application rollers. They will allow for slightly bowed edges and don't have to be set perfectly and still give consistent glue lines.

seems almost like something isnt timed right.
your trigger switch is not working properly or its just not in sync with the banding roller or the glue roller (that is if your glue roller isnt spring loaded)