One of my cats sometimes wont eat unless i hold his bowl up to his face

My cats do the same. They’re fussy buggers.
There was a documentary on the BBC a few years ago about domestic cats - the research suggested that because cats are evolutionarily mostly solitary and kill/eat their pray in the wild, they are programmed to eat the freshest food (whereas dogs are generally scavengers that will eat pretty much anything).
Try cleaning out the bowl meticulously before putting food in it. Their sense of smell vs a human is equivalent to a bandana vs the human’s postage stamp.
Btw, a dog’s sense of smell would be a football pitch on the same scale. Interesting eh?

The other thing I’ve been told recently is that if you’ve got two cats, make as big a separation as you can between their eating places, because they feel threatened if they can smell another cat there. Even if they get on with each other.

" he wont eat at all unless he's hungry"? are you trying to force feed it or something? have you tried offering some cat treats like pounce?

He could have a medical condition. Take him to the vet. He could have a blockage or an illness.

Get a raised stand

Look up "raised cat bowls" on Chewy.com
(Everyone wants to be comfortable when they eat)