Thank you all for your response.
What I did is change the blueprint of the flickering material. This way:
Or deleting the Random node and lowering the value to 10 o less.
Now the blink time is slower. so the shadows don’t look as bad as before. It seems that the engine has more time to calculate the lighting and therefore there are fewer anomalies.
But even with this, I’ll dispense with the flicker in the hope of suffering no more issues.
Looked cool but It is not really necessary for the environment.
I will mark this threat as Solved, even if the solution is not exactly what I expected.
Once again, thanks to everyone, especially SÓLíD_SNÁKÉ. I learned some interesting things that I didn’t think of.