Recently starts to show a bug with refraction.
On a sprite particles with single material in which there is some opaque parts, refraction of the same material is applied differently from different viewing angles.
Like from some angles it takes into account opaque part of the spite and distort it, and from others it doesn’t.
Before 4.13 version it worked as distorting background and overlays opaque parts over it. Now it switches on different angles. Or more like different hemispheres as there is only two switches depending on angle of the camera.
I think it’s related only to Separate translucency but I may be wrong.
On the screenshot there is a single sprite particle with single material. I just rotated the camera a bit.
Refraction Depth here is 0, but changing it doesn’t do much.