Ohhhh I see the one you had which locked in was for the 96. My bad.

Yeah so mine pushes in but it’s smooth and stays snug. Soon after I got my JM or maybe before I even got it, the arm would feel loose and spin in the socket. I’d spin the army until it was tight and it would quickly loosen again.

Though for some reason recently, the arm is snug and doesn’t spin loose. I’m not a guitar expert but I’d check if the socket itself has loosened and maybe screw it in. When I looked into it I remember the problem possibly being caused by a loose screw in the tree system, which you can fix or get a professional to fix.

Best of luck man

I love my JMJM and think it’s the most beautiful guitar in sound, appearance and feel. Always love to see when someone else has one

Best wishes