I had the same issues as Tim, trying to connect my CGEM-II via the NexStar hand controller/USB.
StellarMate OS 1.7.5

[2023-03-29T18:26:39.926 PDT DEBG ][           org.kde.kstars.ekos] - Connecting  "CGEM II Wired"
[2023-03-29T18:26:39.927 PDT INFO ][           org.kde.kstars.ekos] - "Connecting INDI devices..."
[2023-03-29T18:26:39.943 PDT DEBG ][           org.kde.kstars.indi] - CGEM II Wired : "[DEBUG] Communicating with mount motor controllers... "
[2023-03-29T18:26:39.943 PDT DEBG ][           org.kde.kstars.indi] - CGEM II Wired : "[CAUX] CMD <     GET_VER>  APP ->  AZM "
[2023-03-29T18:26:39.949 PDT DEBG ][           org.kde.kstars.indi] - CGEM II Wired : "[CSER] CMD <3B 03 20 10 FE CF> "
[2023-03-29T18:26:39.949 PDT DEBG ][           org.kde.kstars.indi] - CGEM II Wired : "[CSER] aux_tty_read: 3 "

[2023-03-29T18:26:40.932 PDT INFO ][           org.kde.kstars.indi] - CGEM II Wired :  "[ERROR] Timeout error "
[2023-03-29T18:26:40.933 PDT INFO ][           org.kde.kstars.indi] - CGEM II Wired :  "[ERROR] Got no response from target ALT or AZM. "
[2023-03-29T18:26:40.935 PDT INFO ][           org.kde.kstars.indi] - CGEM II Wired :  "[ERROR] Cannot continue without connection to motor controllers. "
[2023-03-29T18:26:40.935 PDT DEBG ][           org.kde.kstars.indi] - CGEM II Wired : "[DEBUG] Handshake failed. "

However, I could connect to it via the CGEM-II Wifi...
[2023-03-29T18:19:48.201 PDT DEBG ][           org.kde.kstars.indi] - < CGEM II WiFi >: < Firmware Info >
[2023-03-29T18:19:48.216 PDT INFO ][           org.kde.kstars.indi] - CGEM II WiFi :  "[INFO] Mount is parked. "
[2023-03-29T18:19:48.217 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[DEBUG] InitPark Axis1 0.00 Axis2 0.00 "
[2023-03-29T18:19:48.217 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[DEBUG] Setting Default Park Axis1 to 4194304.00 "
[2023-03-29T18:19:48.217 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[DEBUG] Setting Default Park Axis2 to 4194304.00 "
[2023-03-29T18:19:48.257 PDT INFO ][           org.kde.kstars.indi] - CGEM II WiFi :  "[INFO] Loading device configuration... "
[2023-03-29T18:19:48.259 PDT INFO ][           org.kde.kstars.indi] - CGEM II WiFi :  "[INFO] Debug is disabled. "
[2023-03-29T18:19:48.260 PDT INFO ][           org.kde.kstars.ekos] - "Re-enabling debug logging for CGEM II WiFi..."
<<skipping location-specific information>>
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CAUX] CMD <MC_GET_POSITION>  APP ->  AZM "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CSER] CMD <3B 03 20 10 01 CC> "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CSER] RES <3B 06 10 20 01 00 00 05 C4> "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CAUX] RES <MC_GET_POSITION>  AZM ->  APP [00 00 05] "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CAUX] CMD <MC_GET_POSITION>  APP ->  ALT "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CSER] CMD <3B 03 20 11 01 CB> "
[2023-03-29T18:19:48.719 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CSER] RES <3B 06 11 20 01 FF FF FB CF> "
[2023-03-29T18:19:48.720 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[CAUX] RES <MC_GET_POSITION>  ALT ->  APP [FF FF FB] "
[2023-03-29T18:19:48.720 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[DEBUG] Encoder [Axis1: 5 --> LST:  5:49:34 HA: -12:00:00 RA: 17:49:34] [Axis2: 16777211 --> DE: -0:00:00] "
[2023-03-29T18:19:48.721 PDT DEBG ][           org.kde.kstars.indi] - CGEM II WiFi : "[ALIGNMENT] Mount -> Sky RA: 17:49:34 DE: -0:00:00 AZ:  0:00:16 AL: -50:34:04 HA: -8:16:14 Pier: PIER_EAST "


Read More...