What would turn a shift pin into a drill bit?

115 merc 4 cyl 2 stroke. On my 6th shift cam. New cam and follower kit today. 3rd follower kit. Dyed the cam groove. shifted to reverse 20 times without engine running. First pic. It looks perfect.
Start engine, I shift one time into reverse. let run for 10 seconds and kill engine. It won't shift out of reverse. See 2nd pic. Pin has drilled a hole in cam. I sanded the inner bore of shaft. Pin fell in and out.
I think the pointed end needs more friction, so it holds the pin still. I thought I had good alignment. My wifes phone takes better zoom pics then my phone. Any thoughts on what would make the pin spin??

I machined a bushing that is the same as prop shaft that fits bearing on rev gear .(1.000) I put .375 hole in that bushing. Put in rev gear , put precision .375 pin with point ground on.
The new cam is .021 below center of rev bearing. Checked with microscope.
The ID of prop shaft has a rough finish and bigger at end of shaft.
Thinking this unit has been pulling a shift pin sideways since 93. Back in 2020 stuff wore to a point that the shaft now grabs the pin and spins it.( this is a very low hour motor).
I will hone the shaft. I will need to be .498 to a .492 pin. I will grind .021 off top of cam and JB weld on .021 shim on bottom???
I know I have been posting some wacko unseen things, but here I am with some info and looking for any thoughts.

8th cam... 4th pin Honed prop shaft, ground and shimmed cam... 1 week wait for parts. Shifted 30 times without engine running... looked good. Ran in reverse for 10 seconds... is now locked in reverse.