Advice on grumpy bun!

Hi :wave:
Sorry if this has been asked before but I've gone through the a few posts and cant find any answer.
We have just finished the main part of our brand new hutch, and have put our bonded pair in, complete with their old toys and bits. They were let out as usual in the garden for a run with the other bunnies, then put in for while and then covered for the evening.
The next morning Charcoal my male was very 'grumpy' (as I put it) he would eventually come to the front of the hutch but isn't his usual self. He is still eating and drinking, and so is Smudge his partner. She seems to be 'off' too but not as bad as Charcoal. I've checked him over and cant see anything, and he's still pooing and weeing. When out in the garden both are fine.
Could it be because they have been moved to a new hutch? Concerned now

it could be but i think it would settle down can they stil go and play in old hutch? i found this helped when my two moved over... in fact yesterday it rained and they jumped into there old hutch:roll: (even tho they have a nice new huge one!) sometimes buns take a while to get used to new things try putting old bedding and stuff that smells of "them" in there... on the other hand it could be some thing else but if eating and pooing and drinkin i wouldnt worry too much tho some one more expeirianced may suggest something i dont know so good luck x