I have a new townhome with 3 beds upstairs, main floor, and unfinished basement. Main floor will not stay warm. I used to oven to heat the main floor to 68 degrees and it fell to 62 within 1 hour. Getting heat out of the vents but it's not as hot as the vents upstairs.

((I have a new townhome with 3 beds upstairs))

Since your home is new I suggest you contact the builder. The HVAC company needs to visit your home and balance or repair the system duct.