Trucking-on, thanks for posting an update. Great that you found the problem and have carried out a fix, though I suspect it will fail again, at least you know where to look when it does... Of course a new plug is the best way to go, though even at that if the other half of the connection has suffered a measure of heat... in time that situation can act like a disease, relative to any new plug..
Looking at your pics there seems to be quite a bit of burning evident, and in that case there is a reasonable chance that the metal connection will have altered it`s properties to some degree, to the extent that trying to squeeze the connection in the hope of improving contact may not work out as you hope long term.... Perhaps if you cut a few short strands of copper wire and put them into the female side of the connector, that might tighten the connection up to the degree when you push them back together and as such be less susceptible to burning..?
