The RPC call returns immediately without execution on Windows11

[ZhengXinyue]

I encountered an issue where some control commands (e.g., moveByVelocityBodyFrameAsync) have no effect and return immediately on Windows 11, while position-based commands work as expected. Interestingly, the same velocity command works correctly on Ubuntu 22.04.

Environment:

• OS: Windows11
• Unreal Engine version: 5.5.4
• Cosys-AirSim version: Main branch(3.3.0)
• Vehicle: Multirotor (SimpleFlight)

Steps to Reproduce:

• Run the standard Blocks environment in UE 5.5.4.
• Execute the Python script provided below.
• Observe the drone behavior and terminal logs.

Expected Behavior:
The drone should move by velocity for the specified duration (e.g., 5 seconds), and the .join() method should block until completion.

Actual Behavior:
The RPC call returns instantly. Logs show identical timestamps for Start and Finish.

settings.json:

{
  "SeeDocsAt": "https://cosys-lab.github.io/Cosys-AirSim/settings/",
  "SettingsVersion": 2.0,
  "SimMode": "Multirotor",
  "ViewMode": "FlyWithMe",

  "Vehicles": {
    "Drone1": {
      "VehicleType": "SimpleFlight"
    }
  }
}

Test code:

import setup_path
import cosysairsim as airsim
from loguru import logger


client = airsim.MultirotorClient()
client.confirmConnection()
client.enableApiControl(True)

airsim.wait_key('Press any key to takeoff')
logger.info("Taking off...")
client.armDisarm(True)
client.takeoffAsync().join()


airsim.wait_key('Press any key to move vehicle')
logger.info('Start')
# client.moveToPositionAsync(-10, 10, -10, 5).join()
# client.moveToZAsync(-10, 2).join()

client.moveByVelocityBodyFrameAsync(
    0, 0, -3, 5,
    airsim.YawMode(True, 0),
).join()


# client.moveByVelocityZBodyFrameAsync(
#     1, 1, 3, 5,
#     airsim.YawMode(True, 0),
# ).join()


# client.moveByVelocityZAsync(
#     1, 1, 3, 5,
#     airsim.YawMode(True, 0),
# ).join()

# client.moveByVelocityAsync(
#     1, 1, -3, 5,
#     airsim.YawMode(True, 0),
# ).join()

logger.info('Finish')
client.hoverAsync().join()

airsim.wait_key('Press any key to reset to original state')

client.reset()
client.armDisarm(False)

client.enableApiControl(False)

Logs & Evidence:
Scenario A: moveToPositionAsync and moveToZAsync commands (Working correctly)

(all) E:\Cosys-AirSim\PythonClient\multirotor>python hello_drone.py
Connected!
Client Ver:4 (Min Req: 4), Server Ver:4 (Min Req: 4)

Press any key to takeoff
2026-01-28 23:26:47.541 | INFO     | __main__:<module>:11 - Taking off...
Press any key to move vehicle
2026-01-28 23:26:51.959 | INFO     | __main__:<module>:17 - Start
2026-01-28 23:26:56.010 | INFO     | __main__:<module>:43 - Finish
Press any key to reset to original state

As you can see the command takes about 5 seconds.

Scenario B: moveByVelocityBodyFrameAsync and other commands (Buggy)

(all) E:\Cosys-AirSim\PythonClient\multirotor>python hello_drone.py
Connected!
Client Ver:4 (Min Req: 4), Server Ver:4 (Min Req: 4)

Press any key to takeoff
2026-01-28 23:28:21.020 | INFO     | __main__:<module>:11 - Taking off...
Press any key to move vehicle
2026-01-28 23:28:27.013 | INFO     | __main__:<module>:17 - Start
2026-01-28 23:28:27.013 | INFO     | __main__:<module>:43 - Finish
Press any key to reset to original state

The RPC call returns immediately even if I add .join() method. It seems the rpc call fails internally? I don't know what happened.

And I have also built the project in Ubuntu22.04, there are also some control functions that have no effect. But I tried the 'moveByVelocityBodyFrameAsync' function and succeeded.