Not able to connect to Unity when training policy

[santurini]

I was trying to train a policy from scratch like this and the model starts actually training but Unity stays on the main page:

python run_drone_control.py --train 1 --render 1

Even if in the output I have this message:

[UnityBridge]  Initializing ZMQ connection!
[UnityBridge]  Initializing ZMQ connections done!
[VecEnv]       Flightmare Bridge is created.

And when I run the test with the saved weights it all works fine:

python run_drone_control.py --train 0 --render 1 --weight /path/to/weight

So my question is, does the Unity rendering work only for testing or it can be used also to monitor the training?