House batteries didn't charge while driving

Your alternator is good, or your engine battery would be dead, check the battery disconnect switches, usually near the entry door, make sure the house/aux batteries are in the on/connected position, they should stay that way until you put the rv in storage
In disconnect mode very little will work, just like dead batteries, and they might not even charge from shore power.
I'm not familiar with the options for your rv
A whole house inverter powering an electric appliance will suck the house batteries dead,
Check to see if the water heater or fridge is set on for 120v, should be set for propane aka LP unless on Shore power

The house battery voltage should jump a full volt as you start the main engine.
Polarity matters so double check. Plug in the RV and see if the house battery starts charging.

Otherwise for charging en route you need to poke along the charging cable from the battery to the isolator and if needed back to the alternator. Along the way you will find voltage jumps up at some point. You will need to repair, replace, clean, tighten, or adjust the component at that spot. Generally the issue will be at a connection, not mid wire in some blind area.

Good luck. Post what you find.

Thank you. We just picked up a volt meter and will see what that says. I should mention we are new full-time rvers and this is a used rig. I appreciate your input. I'm glad we're at least parked and safe for the night, going to troubleshoot and look at fuses and such in the morning. All input/thoughts still welcome in the meantime!

I just corrected a similar problem where I had a dead chassis battery. The battery was new but there was a draw from the alternator which fried the new battery. My jacks won't work. Problem finally solved.

It could be any of the those or it could be as simple as a blown fuse in your charge line. It could take four hours to recharge your house batteries and your drive today was not that long. Do you have a volt meter to check your house batteries?