After spaying - how long before going back with male?

So i have a 3 yr old neutered male and a 6 mth old female. They have always got along wonderfully until the last few days when he has been chasing and nipping her back end. Yesterday he had drawn a little blood
She was booked in for a spay next week so I have brought it forward and she is being done today as i think the problem is probably that she has reached maturity and may have a different scent which is affecting him.

I have arrange seperate living space for them but rightnext to each other so they can smell and touch (just about) is this a good idea or not? How long should i wait before they go back together?
Normally they get on great until last few days. He never mounts her, just chasing and nipping of late. Its always him who starts it.

Can you offer any advice on what to do going forward please?

I think its 6 weeks possible 8 weeks, males are 6 but females might be wee bit longer, but I might be wrong.

I usually keep any does on bed rest for a week or so after their spay. I have a hutch that I bring into the back porch so they are rested before going outside.

I would also try to introduce them again when she is recovered on neutral territory (like a bathroom) just to make sure that everything is OK. She will have reached sexual maturity so that is maybe why he is reacting the way he is. You need to make sure that the dominance order hasn't been affected by the operation. Take it slowly and I am sure it will be OK.