Loss of air on rear axel and then…. Update...

Don't ya just hate intermittent problems? I'd rather it break so I (or a tech) could find the break. But, anyway, you got lucky and were able to go camping and return home without too much issue. But, one of the first things I'd do is, get ahold of that company that came out to attempt to fix your rig and then, drove off without charging anything. Man, that's rare. I'd send them a seriously nice letter and maybe even MotorHome magazine too. I wouldn't expect a "no charge" each and every time but, the fact that they took the time to drive out and even climb under your rig cost's them money. Nice company.
Don't know what your problem is with your air system but, if and when you find out, please surely post it so that others, if they should develop the same issues, might look at the same fix. Good luck.
Scott