Slow kitchen drain

Ok, this is a weird one, and not very important. I've just never seen it before.

I just built a new house and the kitchen sink drain works perfectly when I run cold water into it. But when I run hot water, it backs up just a bit. Not enough to fill the sink, but enough to fill the basket/strainer and a little in the bottom of the sink. If I switch back to cold it quickly drains as it should. Mixed (lukewarm) water drains ok, too. Trap/trap arm/tail piece/etc all brand new with no obstructions.

I can live with it, just curious if anyone has ever seen this before.

Possibly you're getting more water flow out of your hot water pipe than you are out of the cold pipe . If drain & vent are installed correctly you shouldn't have any backup . Can't say I ever encountered this problem so just guessing .