Blowing cold air?

We replaced our gas furnace with heat pumps on 12/26/2025. For the second time now, after heating to the set temperature, it blasted cold air for the longest time. I thought it was just taking time to heat up but after an hour or more, I thought it might be a sensor issue and unpair the extra sensor that came with the ecobee smart thermostat. But damn, it still blew cold air. I had to turn the temperature down so that heating would stop running since it wasn’t actually heating the house. We called our HVAC guy and scheduled an appointment for tomorrow. Any thoughts?