Hi,
Is it a connector within the flex or a connector that plugs into the body of the light unit ?
Basically any such connector thats getting hotter than the surrounding area is faulty or under rated.
You could try cleaning the plug and socket, but long term you are better replacing it.
If the socket is part of the light unit, it could be an internal fault like a 'dry ' joint, needing the socket resoldering or replacing.
Thanks Dino, I've also placed this on a direct socket rather than on an extension which has made some difference.Just found this uk supplier selling inline plugs and sockets rated at 5A, though they do need to be soldered on.
https://www.ebay.co.uk/itm/5-5mm-x-...218077?hash=item484d38df1d:g:1wwAAOSwv0tVCa72
...of course it does not overcome the original problem of the connectors being under rated, better using something rated at 7/8 or 10 Amp to avoid the overheating.