If you have selected Fan Forced as your heating type Mysa will default to the short cycling option. This can be changed to extend the cycling time and avoid the rapid cycling you are experiencing by navigating to the settings of the thermostat. From here you will have the option to select the Long option.
Additionally, you could select Radiant Heat mode which will only activate the heater when the set temperature falls by 0.5° C (1° F). For more information on the cycle times go here.