Could this be a hint:

"""
GM (General MIDI) is also present, as a bank in the PROG section. The sounds starting with the letter "G" follow the GM protocol and can be used with thousands of available MIDI files.
"""

If your selected bank is not the GM bank, could it be that the Korg is finding the guitar in another bank?

My Kawai defaults to non-GM, so I see this issue.

Jazz relative beginner, starting at a much older age than was helpful.
AVL:MXE Linux; Windows 11
BIAB2025 Audiophile, a bunch of other software.
Kawai MP6, Ui24R, Focusrite Saffire Pro40 and Scarletts
.