Stubborn female refusing to groom a potential friend...

Hiya, bit of background info... I had successfully bonded a 1yr old male with a 6mth old female, but sadly our male died at just 3.5yrs. So we adopted another male... bonding isn't going well or badly - we're in a stalemate situation! Male is desperate for some lovin', but female is being very stubborn and refusing to groom him. He then gets a bit pushy, and she gets nippy, as does he... they will happily sit 1 metre away and clean and eat, but its like they've decided they'll live alongside one another but never together. Is there any hope for these two? What can I try? (tried banana on heads, they both looked embarrassed and didn't go for it lol. Also just to say both are neutered). Many thanks for any help u can offer, as we just can't seem to get past this.

Ignoring is a good sign. Let them get to know each other SLOWLY in their own time. Many bonds fail due to rushing. Dont worry about lack of grooming. They are doing just fine.

I understand that this is not going well Is there anyone in Cornwall that can offer bonding assistance here?

They have had a fight now, I had to separate them as was fearful of injury. If anyone in cornwall can help that would be amazing.