home button no longer functions after I replaced my lightning port

It might be a faulty part.It depends if you changed it by yourself or you replaced it at a repair shop.

The part might be good but the connection of the lightning cable with the motherboard is not tight.

Check also the pins from the charging cable.They should be lifted a bit( 1 1/2 - 2 mm) so they'll touch the actual home button golden contacts ( located on the LCD side on the bottom frame) when your closing the frame with the LCD back on the phone.

If it is an iPhone 5S disregard the pins problem, just check the motherboard connection

Check also if your phone was water damaged.

Good luck!