Any ideas welcome

[NellieTheElephant1]

I moved with my 2 cats into my DP's house 3 and a half weeks ago (50 miles from where I used to live). DP also has a cat but the house is big enough for 3 cats to have their own space.
Anyway, after 3 weeks indoors my neutered boy cat escaped at the weekend and won't come back inside. He comes into the garden at night and I have been going out to feed him. He won't come close enough for me to grab him, and even if he did he hates being picked up and has scratched me badly in the past.
I've contacted the local Cats Protection to see if they have a trap I could borrow, but does anyone here have any ideas please?

Can you leave the door open and his food just inside the door? Keep moving it back a little until you’re able to close the door behind him.

Obviously lock/block the cat flap if you try this!

Does he have a shelter in the back garden to sleep in? If so, just wondered if you could very gradually move it closer to the house, re acclimatising him to his new home.
Any idea why he is behaving this way? Did he have a fight with the resident cat? If so maybe he is still scared to come in.
Good luck, it's encouraging that he is still returning to the garden every day