I’ve set Blend Mode to Translucent and changed Lighting Mode to Volumentric Direction (though the same issue occurs with Volumetric NonDirectional); everything else is default.
Happy to try and upload a video or answer any questions to make the issue clearer if necessary.
I forgot to add that the same issue occurs without the clamp on the refraction input and its not a static issue. The best way I can describe it is that the refraction will only apply to a certain amount of screenspace.
Changing the clamp on the refraction seems to increase the amount of screenspace that the refraction will apply to, though obviously this reduces the refraction amount as well.
Im thinking this is some sort of processing limitation; i’m going to check if it continues to happen in an actual build.
Clamping the refraction value to be between 0.9 and 1 has effectively solved the issue; I am going to assume this was caused by some sort of processing cap for refractive materials