Undo the jack plate so the socket is hanging out of the guitar, then you can see if the jack is making proper contact with the socket. And if you get normal sound when its out, then there's still contact between the jack socket and the shielding occurring.
It does sound like the tip of the jack is making initial contact with the tip contact when it first touches, but when you push it all the way in, the tip contact is then being pressed sideways against the shielding.
Last edited by Simon Barden; 04-06-2021 at 05:19 AM.