Simple window rendering problem with pyGLFW and Ubuntu on Wayland

I'm using Ubuntu 20.04.3 and Python 3.8.10 on x64 CPU. Logged in to Ubuntu on Wayland. This simple test of pyGLFW 2.4.0:

import glfw

glfw.init()
window = glfw.create_window(640, 480, "Hello World", None, None)
glfw.make_context_current(window)

while not glfw.window_should_close(window):
  glfw.swap_buffers(window)
  glfw.poll_events()

glfw.terminate()

produces a defective window:

with this warning:

/home/paul/vis/.vis/lib/python3.8/site-packages/glfw/__init__.py:906: GLFWError: (65544) b'Wayland: Focusing a window requires user interaction'
  warnings.warn(message, GLFWError)

With normal login (X11?) the window produced by this script looks fine:

What is the problem? I prefer using Wayland, because I can't fix screen tearing on this PC with X11. Yes, I tried many helpful hints from interwebs.