I have a 70 Corvette, I’m having problems with my shifter not locking properly, it’s a automatic shifter, I can shift it from neutral to reverse without having to push the button. I have adjusted the shift linkage on the transmission several times, but doesn’t seems to help. I have removed the shifter and disassemble it, can’t really see anything wrong, the spring is not broken, the button does have some up and down movement before it contacts the spring. Please help 🤔

[AW edited to fix problem with message subject]