Well after stripping the gearbox, checking each gear, running each idle gear on its own. found no issues.
So I put it back together & still there was binding

.
I had it suggested to me it might disappear after a few runs by Buggy0

Mid motor guard time. Screw in the M310 set screw & screw the mount down over it.

yuk

Better

Place the motor guard & motor plate over the gearbox.

The start screwing the plate & mount place.

Time to bolt the rear shock tower into place.

Screw two 4x8 ball studs each side stabilizer seat.

Locate the shock tower onto the stabilizer seat.

& screw into place with the two M3x10 button heads!

Ready the motor mount stiffener with its hardwear

End result!!