The Drive motor to max speed portion of the spin cycle doesn't engage all the time and frequently leaves us with a bunch of soggy wet clothes that must be wrung out by hand. There is no error code that displays when this happens, so I'm not sure how to proceed. Any suggestions would be greatly appreciated.

Yes that was the first place I looked.

If you are 100% that it is capable of draining then there are a few more possibilities.
1) Make sure your drain hose isn't allowing water to siphon back into machine when pump stops. If the end is submerged in the trap it can pull water in. You want to hear water dropping through air into the drain. It sounds implausible but I've seen it and it can happen sporadically.

2) I seem to recall fighting one of these for some reason a few years back and it being either the door switch or lock.

3) If it does pump out to fairly empty and begin low speed spin then at that point when you'd expect higher speeds disconnect the end of the pressure hose from the pressure switch. Don't unplug the switch as your goal is to make the machine think there is no water inside. If it proceeds to high speed spin expect some significant shaking.

I wish I could recall better but these smaller machines are rare around me and I haven't seen one in a year or so.

That's about right. It'll never be empty. The pump cannot push air.