I have 3 levels, and when the scale of the viewport changes, the resolution of the game changes too. But at this level it turns off. how to fix it?
Yes, this is a shader issue I ran into when I was porting over my shaders from Unreal Engine 4 to 5. You will have to go into the shader code and make sure that all paths return the proper number of channels. Usually the issue lies within the scene texture output.
Alternatively you can purchase the best collection of shaders there is: Elias Wick | Advanced Pixelation 
yes, thank you!! I already realized that the problem with the shader and fixed it