diffraction - Why does red light bend less than violet? "BUT" , sound diffracts more than light

We can hear the sound that coming from the other room, but we can't see the light coming as well.

And in this case, sound diffracts more than light because of a wavelength of sound is bigger than light.

Now we can say that in general, waves with lower wavelength can curve around a corner less than a wave with high wavelength like sound.

So when a beam of light passes through a glass, the Violet (a lower wavelength ) diffracts more than the Red color ( a large wavelength)

And here I couldn't understand it because the two concepts should be the same and in real they're not.

Thank you