Young Gopher Snake suddenly refusing food.

[CNR]

Hello, everyone!
I am new to this site although not new to herps.
My question is this. Almost two months ago, I caught a hatchling goper snake on my property. Named her Serpie. Set her up in housekeeping in a 10 gallon tank with wire lid with safety clips. Under tank heat on one side, bask light and reptile uvb-uva light on other side. Bark substrate. Oxasalis plant in corner. Water dish. Hide. The whole nine yards. She was eating TWO small F/T pinky mice every other day! Always hungry! Then she took a few days off to shed. Back on feeding schedule.
Then, I decided to upgrade her tank to a 20 gal low, with locking lid for herps. Take is set up the same with a few additions for serpent enrichment. Changed her substrate to aspen shreds, (reccommended).
Ordered a bunch of frozen pinky mice from online source. They look fabulous, although slightly larger than what she was used to.
It has been several days now, and she STILL refuses them. (I thaw them the exact same way I did her original pinkys).
I leave them for a few hours, then throw them out. Next day, I try again. Same thing. This went on for a week, when I got more 9f the local, small pinkys like she had before. She has refused this mornings offering. Again.
Am I being overly concerned here? She is cheerful, active and in good weight.
Advice, please??
*sorry for the long, initial post. Just trying to give you background!*

[chairman]

Pines/bulls/gophers are ravenous eaters but feeding that close together was probably too much. The snake should be eating 10% of its weight every 5, 7, 10, or 14 days depending on its size/age/breeding status.

I would give the snake time to get used to its surroundings, probably about a week, and then try offering food at night. I'd leave the mouse in overnight to give the snake a chance to eat privately.