OK, don’t blast me but this was on Gardeners World last night. This is the month of repotting a citrus. It will need repotting but he [from TV] used the same pot from what I could see. He took out his citrus. Teased off the old compost from the outside of the root ball and cut some of the roots but only to make it fit a little easier when put back into the pot. He mixed grit with compost [can’t remember variety] and also topped up with some good quality garden compost.
The yellowing leaves is a sign of a lack of nutrients in the soil si repotting would help that for a few months but you would need some sort of feed especially during the fruit growth period.
I’m only an amateur gardener so best do some research but the little I know has been shared…