Bad Starter or Starter Solenoid?

No. If the bendix is engaging then the starter may not be spinning over. Might be a problem with the starter or maybe something to do with how the gear on the starter is trying to engage with the teeth on the converter or flywheel. I'd pull it and bench test it. Make sure it spins free on the bench. I put the starter in a vise, jumper cables to a spare battery. Negative of the battery to the case of the starter. Positive of the battery to the same post the red battery cable connects to. Then use an insulated screwdriver to jump across the contact to engage the bendix.