FWIW a friend was once having trouble with his card, the head wasn’t recognising if as a valid card. I gave the chip part of it a gentle going over with a pencil rubber, and it pulled a load of crap/grease/sweat out of the gaps between the gold segments and it sorted it.
Personally, I always handle mine by the edges, keep it in a little wallet when not in use and NEVER hand it over to the oily office oik for downloading. I’ll put it in the machine myself.