Error at the end of discrete and contious (plt.plot)

[Nodmgatall]

Be gentle this is my first issue I ever write. :)
First thank you for your work, I am trying to use this for seminar paper and this was the first actually executing repo I found.
To the issue:
I get the following error at the end of the execution in the plt.plot(res) line:

QObject::moveToThread: Current thread (0x557e202d2ac0) is not the object's thread (0x557e1fa88a40).
Cannot move to target thread (0x557e202d2ac0)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/oliverheidmann/.local/lib/python3.8/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb, dxcb, xcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx.

zsh: abort (core dumped)  python continuous_A3C.py

After some googeling I found that this seems to be an issue with threading.
My idea is, that 'res' is still bound to a thread and as such the plt.plot(res) throws this error.
But that is just a first guess.

When removing the plotting lines and saving res with np.save("fileName", res) the program executes without an error.
Any ideas?
Best regards
NodmGatall