Sounds like dirty contact points to me. If other carts play fine, likely not the device. If that is the only cart doing this try cleaning the contacts. Use a pencil erasure to rub the contacts, length ways not cross ways, until clean and shiny. Then use either 90+% IPA or electronic contact cleaner to finish it off.
If the device is the culprit, harder to clean. I use a coffee filter folded into the shape and rough thickness of contact slot, lightly covered in 90+% IPA. Insert and remove repeatedly just like you would a cart, to clean the devices cart slot contacts.