If the starter is spinning, but not turning the engine, it's possibly a bad starter solenoid (most likely), or you've stripped some teeth from the flywheel, which have now lined up with the starter gear (less likely).
You say a "newer starter." What was the previous issue? Maybe your previous starter issue was really teeth missing from the flywheel and now it's lined up with them again.
Missing teeth doesn't seem to happen very often these days, but my son recently bought a 2006 Cobalt with 140,000 miles that he intends to build a kit-car from and he just discovered it has this problem. (He knew when it bought it that there was some kind of starter issue.)