Heater issue

I have a 2004 tailgater toyhauler, I did the digital thermostat conversion about a year ago and have had several trips without issues, this trip over New Years I had this issue, when I turned it on at night it would cycle 3-4 times (coming up to temp, cooling down and kick back on) and the the next time the thermostat would show that it was calling for heat but the furnace would not turn on. The first night I thought I ran out of propane so I switched tanks, the next night it did the same thing though with a full tank of propane. I found if I shut off the thermostat and then put it back on heat it would turn right back on. Again it would cycle 3-4 time the next hour or more and then not start again unless I shut it off and then turned it back on.

Not sure if this could be a thermostat issue or a heater issue, open to suggestions.

Thanks