Any idea why my KPG89D software won't read it? Or, anyone know of a way to force it into wide band with 89DN software?
If it's running narrow band firmware, it's not going to let you program it with the older software.
The only way around it is to try to find older firmware. I've never tried forcing older firmware into an updated radio, but it might work. Or it might not.
Other option is to contact Kenwood and request a W-License. That'll reopen the wide band programming capability. You'll need to supply a legit serial number for the software activation, not one of the default ones that may be floating in the dark corners of the web. They may charge you (I think it used to be 80 bucks or so, not sure what it is now) and they'll issue you a new serial number that you activate your software with wide band capability. You'll need to provide proof of eligibility for wide band channels, that could be your ham license, GMRS license, or a Part 90 license that has not been impacted by the narrow banding requirement.