Test connection failed with physical target machine (Debian 13.7 Linux) using the Simulink Real-Time Linux Devices toolbox.

Test connection failed with target physical machine (Debian 13.7 Linux) using the Simulink Real-Time Linux Devices toolbox.
MQTTX installed on Windows development machine; send/receive tests with Debian target are successful.
All prior tests pass, only MQTT verification step throws SSH authorization returned -18. Manual SSH from Windows cmd/PuTTY works fine.
### Simulink Real-Time Test Suite
### Target IP address is: "192.168.31.36"
### Test 1, Ping target computer '192.168.31.36' using system ping: ... OK
### Test 2, Ping target computer '192.168.31.36' using matlab SSH object: ...OK
### Test 3, Verify file transfer connectivity: ...
verifying file transfer with FTP ... OK
### Test 4, Verify target image version: ...OK
### Test 5, Verify target environment file: ...OK
### Test 6, Verify MQTT connectivity: ...错误使用 slrealtime.testSetup
sshDevice error occurred during init. SSH authorization returned -18

出错 slrealtime.testSetup

[Torsten]

Contact support:

https://uk.mathworks.com/support/contact_us.html