I crashed my drone and one motor was not turning at all and one was hitching. I bought and replaced both motors. Now three are running. Then I replaced the ESC card on the one that is not working. IT still is only what I would describe as hitching. Any ideas what next?

Check all cables to see if they are in good condition and correctly connected. If the motors and ESC’s are new, then they probably aren't the culprit...

Check that all the Naza components are in good shape and in the correct position.

Use the Assistant and update and reconfigure everything, just in case.

Are the led messages normal?

Oh, I forgot.

The new ESC’s will probably need recalibration... I don't know about DJI ones, but the Maytech I use for my octo do.