Have you had the lightning port checked for fluff?
I've blown it out, and can't see any obstruction or contamination.Some more cleaning might help I suppose.
Testing just now we have two charging cables in the kitchen, each can be inserted either way round so four possible connections. All four work with other phones just by plugging in. With my phone three of four never work. One cable, one way round, will sometimes work but only if there's pressure pushing the connector at an angle to one side. But often that doesnt work either, sometimes nothing, sometimes the phone buzzes but doesn't start charging, sometimes it goes on charge but stops after a couple of seconds.
