Hi Sek,
Oh no! I'm sorry to hear that your thermostat short cycles on heat upon initial setup. Please gather the power readings of your Nest Thermostat by going to Settings > Technical Info > Power (Battery, VOC, VIN, and lIN) for Nest Learning Thermostat and Nest Thermostat E and to Settings > Equipment > Power Info (VIN, IIN, PS-*) for Nest Thermostat 2020. Also, kindly check your air fifilter, as a clogged filter might cause a similar symptom. If the air filter is dirty and needs to be changed, replace the air filter and let us know if the issue continues after you change the filter. Refer to the Air filters and filter reminders article for more details.
Keep us posted. We're happy to help.
Best.
Zoe
