I'm having a very similar problem with my new CPC 800, which I have had for less than a month. I am concerned the Az motor is not working. The motor worked on the first two outings. Both my Nexstar and Starsense hand controllers have been updated to the latest firmware.
I started the night using CPWI with the Starsense hand controller. Upon startup, the Alt motor went north to Polaris but then hung up. I thought that it was due to sky haze and difficulty finding stars, but after 20 minutes, I turned everything off, disconnected and started again. This happened twice more.
I then disconnected the Starsense controller and camera, turned everything off, and tried using CPWI with the Nexstar hand controller. Again, no luck with Az.
I then disconnected everything and restarted with just the Nexstar hand controller. Alt worked fine. Az didn't work.
I checked to make certain the Az clutch was tightened. It was. I then loosened the Az clutch and confirmed I had free movement in both directions.
I set the mount up in my living room this morning using the Nexstar hand controller, and same result. Alt works fine; no Az movement or noise.
The only thing I can think of is that as I put the mount on the tripod at the beginning of the evening, there was some resistance while I spun the mount to set the mount on the mounting bolts. However, the mount was moving freely before I started the above process.