So is the motor turning over with the starter?
Sounds like the new starter motor is bad.
You are going to have to replace the starter motor and retest.
This should take care of your problem.
Just be sure the flywheel is in good shape.
Inspect the flywheel very carefully when the starter is out and make sure that there are no teeth missing and that the flywheel is not moving in and out as the motor is turned slowly. You can do this my hand at the crankshaft bolt.
So then the problem must be on your car.
Double check the flywheel. It might be cracked.
Turn the motor over slow and watch the flywheel.
It might move in and out as it turns.
Thanks for the accept!
Let me know what you find!