intermittent radio controls

[DomP182]

I've asked and searched this before but it's doing my nut in now. My radio steering wheel controls keep disconnecting so I pull the radio out, pull the plug, push it back in again and it will work for may be 1/2 an hour. The plug is in tight and the cable doesn't appear snagged though it surely must be that as I push the radio back in it disrupts the connection?
Any ideas?

 

[DomP182]

Tried again, worked for a day then stopped. Surely I'm not the only one with this problem!