Hey, that looks pretty good! The lighting and materials are great but noticed a few things maybe you can clarify for me.

In that opening shot I noticed what appeared to be shadows on the xmas tree suddenly pop on? Or maybe geometry was suddenly appearing out of nowhere? If you look close you'll see it as the camera is pulling away from the closeup. What is causing that? I've seen that kind of thing before in eevee animations so I'm curious why that happens. Also, what would the biggest differences be if you rendered this in Cycles?

Oh, I don't know if you realized this but your thumbnail says 4k UHD, but the highest setting I can watch it on youtube is 2k.