In case you still haven't found the exact answer to your question, if you have the SynScan controller attached to the mount and the USB attached via the serial adapter on the hand controller, go to Utilities on the hand controller and select PC Direct mode. This will allow the software to connect to the mount using the hand controller as a pass-through. I had the same issue as you with my new Atlas II EQ-G mount which uses the GS Server utility as the ASCOM driver. If the hand controller is not in PC Direct mode, the hand controller will take control of the mount and block all other communication channels. This is a change from the SynScan controllers from 5 years ago where the pass-through functionality was automatic once you attached the USB-Serial adapter.

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