Why is my cel still on?

I have had my 2019 jeep compass to the dealer twice this
week for a check engine light.  The first time, they told me
there were no codes, and everything was fine.  It stayed off
about 24 hours, then came back on.  The second time, the
heat controls on the computer screen weren't registering
even though the heat was working.  I took it back to the
dealer, but they said there are still no codes, however they
did have to replace the blend door actuator.   Again, lasted
about 24 hours, and the light is now back on and the heat
controls are doing the same thing.  Anyone have any
ideas?? The car is barely 6 months old.