During first the choir practice, there is a member in back with a blue COVID face mask still on and quickly removes it.
At 7:14 when the cuckoo clock strikes 6 is it 6 am or pm because in Vermont at that time of year it would be dark no matter if it was 6am or 6pm.
When Hannah and Mr. Cooper leave the museum, he gets into the passenger side of the truck with Hannah driving. Since Hannah and Mr. Cooper meet at the museum, he would not have ridden with her to leave - especially after their conversation.
When Hannah and Mr. Cooper leave the museum and get into the truck, you see the truck from the rear. The truck is missing the back window, which has been replaced with a piece of plastic.
In the previous three installments of the Christmas in Evergreen movies, Hannah and by association Thomas and David's family name was Tucker. In this movie, it has changed to Turner.