Dave Platt wrote:
One cause: some N-connector adapters floating around out there have
center pins which are either too large in diameter, improperly
tapered, or which protrude too far "forwards". I suspect that male N
connectors, if improperly installed, can have the same problem (the
pin is pushed too far into the connector).

With some types of cable, there is a tendency for the inner conductor
to "lengthen" relative to the outer shield when the cable is repeatedly
wound and unwound in a small radius.

This can sometimes push out the connector pin a little.