Consider replacing the connector with a Marinco type connector, which has a secondary sleeve which screws onto the white, threaded outside rim of the rig's socket. To date, I have not had this problem, but if I have it in the future that will be my solution since that is the type of shore power connection that our boat uses. Another advantage is that it provides a waterproof connection. Hope this helps. Here is one way of possibly doing it with just an outer sleeve:
http://www.tweetys.com/weatherproofcover-50amp.aspx
It will require a disassembly of the connector itself.
Bingo
__________________
Bingo and Cathy - Our adventures begin in the hills of WV. We are
blessed by our 2014 3850FL Big Sky (previous 2011 3750FL and 2007 3400RL) that we pull with a 2007 Chevy Silverado Classic DRW CC dually.