PSDK V3.5 / M300 RTK with H20T and Z30 - GetCameraType only works for main position

Hello,
both cameras are connected to main mount position (H20T) and vice mount postion 2 (Z30). Both are working in the liveview sample.

If I try to get the camera types in a loop. Only the first camera is reported and for the second camera a get error messages. Cam1 = 43 which is the H20T. Cam2/3 = 0

The error messages are:
[11.039][linker]-[Warn]-[DjiCommand_SendAsyncHandle:875) Command async send retry: index = 0, retryTimes = 3, cmdSet = 0, cmdId = 1
[11.541][linker]-[Warn]-[DjiCommand_SendAsyncHandle:875) Command async send retry: index = 0, retryTimes = 2, cmdSet = 0, cmdId = 1
[12.043][linker]-[Warn]-[DjiCommand_SendAsyncHandle:875) Command async send retry: index = 0, retryTimes = 1, cmdSet = 0, cmdId = 1
[12.544][linker]-[Error]-[DjiCommand_SendAsyncHandle:887) Command async send error 0
[12.544][linker]-[Error]-[DjiCommand_SendSync:488) sendSync callback timeout
[12.544][cmu]-[Error]-[DjiCameraManager_GetCameraType:397) Get mount position 3 camera version error,error code: 0x000000E1.
[12.544][cmu]-[Error]-[DjiCameraManager_GetCameraType:398) Execution timeout. Suggestion : Please contact DJI for help.
[12.544][user]-[Error]-[Psdk:162) Get mounted position 21993 camera's type failed, error code: 0x000000E1

Code:
for (int i = 1; i < 4; i++)
    {
        returnCode = DjiCameraManager_GetCameraType(E_DjiMountPosition(i),
        &cameraType);
        if (returnCode != DJI_ERROR_SYSTEM_MODULE_CODE_SUCCESS) {
            USER_LOG_ERROR("Get mounted position %d camera's type failed, error code:
            0x%08X\r\n", mountPosition, returnCode);
        }
        std::cout << cameraType << endl;
    }

How to get also the type of camera mounte on the vice or third position?

Thank you for your support!

BR,
Michael