I have the same mount. What is your configuration?
If you have Synscan handset, I recommend to use Synscan mount driver. I fixed that driver properly and it is more robust than the Skywatcher Alt-Az mount driver.
Or do you connect the mount directly to your computer?
Disconnect anything else and connect mount, it sounds like it’s conflicting with another USB to serial device..then use the serial mapping tool to map it to a fixed address...
Stellarmate OS on Raspberry pi4b
Skywatcher EQ8 pro, on steel pier
Takahashi FSQ85, FS60cb & Meade 8” SCT (de-forked)
Starlight Xpress SXVR H18, SXVR M25c, Lodestar x2 Guide Camera
Pegasus Ultimate Hub V2 for all USB & Power
Pegasus focus motors on all scopes
INFO 404.881091 sec : Session log file /home/vinnius/.indi/logs/2018-12-30/indi_skywatcherAltAzMount/indi_skywatcherAltAzMount_13:22:32.log
WARNING 616.397137 sec : Communication with /dev/ttyUSB0 @ 9600 failed. Starting Auto Search...
WARNING 711.708942 sec : Communication with /dev/ttyUSB0 @ 9600 failed. Starting Auto Search...
WARNING 811.284954 sec : Communication with /dev/ttyUSB0 @ 9600 failed. Starting Auto Search...