Tested your LP detector lately?

Mine went off at 5:30 in the morning on my last day at the campground last week. I turned off the LP at the tanks and we made the trip home. I tested all connections with both bubble solution and a gas detector and found nothing. I was still concerned enough that I bought a gas pressure gauge and tested again. No pressure loss after 3 hours. It's things like your link that make me so cautious.
I still have no idea what caused the alarm.