My gas furnace does not start when the thermostat is set on 80 but will start if I turn the unit off from the thermaostat and then quickly turn it on. What could be the problem?

Stat could be going bad. https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html#post268260