12 volt positive battery connection issue

started the car at home with no issue to pick up a pizza, turned it off and when I came out the car was dead, nothing turned on.. manually opened the hatch and lifted up on the rear of the positive battery cable and the car came to life when I let go it died again..

rolled up a sock and put it between the battery and the connector to hold it in place to get the car going and drive it home...

whats inside the connector that can cause this intermittent issue, the cable is tightly connected to the post and does not move.can this be fixed or do I need a replacement connector?

 

Im going to look at it again in the day light it was already dark when this happened last night...
will take it apart and check it out

 

you would not come to pick it up anyway,but if you take it as is Ill throw in the rolled up sock to ensure you get home

fixed thanks