Bp1987

So I have a 1996 trans am LT1 M6 tranny. I’m on my 3rd starter, for about a year the 1st starter was fine, it went out so I bought a new one from advanced auto. I started my car about 5 times then the starter would just spin like the bendix wasn’t kicking out. I didn’t investigate much other than bench testing at the store, which it tested fine, I just returned it on warranty. Put the 3rd starter in and it started the car about 3 times then the same thing, would just spin like the bendix wasn’t kicking out.
I investigated this time. Starter tests good on the bench but once installed, the bendix kicks out and meshes with the flywheel. Once it’s in the flywheel it’s stuck and doesn’t retract. While in this position it spins the starter and sounds like the bendix isn’t kicking out (strange right). I can loosen the starter bolts and wiggle the starter and the bendix retracts. What the hell!!??
so I can turn the car engine by hand without issue, compression feels good when I do this and there is no binding in the motor that I can feel. I have tried shimming the starter and it doesn’t help at all. Also I have inspected the flywheel and all teeth are there and appear to be in good shape.
Every now and then when turning the engine by hand and readjusting the starter I get a second where the starter grinds then begins the fast free spin like if the bendix was stuck.
any suggestions?

everything done to car:
1996 LT1,M6,
LT4 hot cam
LT1 561 heads
MSD 6AL ignition
MSD Blaster coil
MSD 8.5 mm wires
MSD pro billet optispark distributor
PaceSetter Long Tube headers
Comp Cam 1.6 RRs
SLP Muffler
Walboro Fuel Pump
Stage 2 clutch
EGR delete
A. I. R. Delete
AC compressor delete
Eiback full suspension