ModernGL context rendering brakes Pygame (nothing appearing on the screen)

Question

On monday i wrote a python script with modernGL that runs a fragment and a vertex shader everything worked fine and I had like 40 FPS. Two days later, I tried to rerun that same script and nothing appeared. All my old scripts that worked too were not functioning this time. So I tried to isolate the problem, and it seems that there is something to do with the context rendering of modernGL; I will explain.

I wrote this code with just the faulty lines. It creates the context and everything then render it but don't display it. Then in the main loop I just want to display a screen with a background color and a Hello World text.

`import moderngl as mgl
import numpy as np

import pygame


init = pygame.init()
print(init)

screen = pygame.display.set_mode([1920, 1080], pygame.RESIZABLE)
clock = pygame.time.Clock()
font = pygame.font.SysFont("Arial", 32)
font2 = pygame.font.SysFont("Arial", 64)
  
SIZE = WIDTH, HEIGHT = int(500), int(500)
COLOR_MODE = "RGBA"

ctx = mgl.create_context()
fbo = ctx.simple_framebuffer(SIZE, components=len(COLOR_MODE))
fbo = ctx.simple_framebuffer(SIZE, components=len(COLOR_MODE))
fbo.use()
vbo = ctx.buffer(np.array([
    # x     y    z     u    v  
     1,  1, 0.0,  1., 1.,
     1, -1, 0.0,  1., -1.,
    -1, -1, 0.0,  -1., -1.,
    -1,  1, 0.0,  -1., 1.,
], dtype=np.float32))

ibo = ctx.buffer(np.array([
    0, 1, 3,
    1, 2, 3,
], dtype=np.int32))

with open('shaders/Fragment.glsl', 'r') as file:
     FS = file.read()

with open('shaders/Vertex.glsl', 'r') as file:
     VS = file.read()

prog = ctx.program(vertex_shader=VS, fragment_shader=FS)
vao = ctx.vertex_array(prog, [(vbo, "3f 2f", "in_vert", "in_uv")], ibo)
vao.render(mode=mgl.TRIANGLES)

run = True
while run:
  screen.fill(255)
  text = font2.render("Hello World", 1, pygame.Color("orange"))
  screen.blit(text, (10,20))

  for event in pygame.event.get():
      if event.type == pygame.QUIT:
        run = False
  pygame.display.update()
pygame.quit()`

The is 3 states with this code. If I just run this, I have a black pygame window: Black window when executing

If I comment the line 21: fbo.use(), then the shader that should be a square image of 500*500 is displayed as the background (but I never asked pygame to show it).: Distorded shader

Then, last case I also comment the line 42:

vao.render(mode=mgl.TRIANGLES)

and then the pygame window looks like what I want. Normal pygame window

For every situation, main loop is well running and the pygame events are working as expected.

I tried to uninstall and reinstall moderngl, pygame and glcontext (even with different older versions) but every time the script don't work.

Also I am sure I didn't modify my scripts, I copied some working backups and they don't work also.

If you have any hints I would be so nice. Thank you!