OpenVino : traffic_counter error with Neural Compute Stick 2

[Robino]

Are you using one of our development environments?

I'm using the image for Raspberry "Raspbian3B_4B.img" that I uploaded today on my rapsberry 4 / 2Go

Describe the issue

I try to use the openvino with Intel Neural Compute Stick 2 on my raspberry
source start_openvino.sh ==> all is good (cv2.version'4.1.1')
cd dev/`` python traffic_counter.py -c config/config.json -m vertical --input videos/highway-orig.mp4'

and I have this strange error:
Traceback (most recent call last): File "traffic_counter.py", line 73, in <module> mog = cv2.bgsegm.createBackgroundSubtractorMOG() AttributeError: module 'cv2' has no attribute 'bgsegm'

Any other information

I tried using source start_py3cv4.sh and it works perfectly.
I tried to reboot and start immediately and no more success.