I guess the programmer of the effect doesn't see any problem - light is tilted, but comes downwards, so the top surface is lighted and that's that, no problem!
As an artist you expect different behaviour. You are not alone. Current bevel behaviour has been filed as a bug six years ago: https://www.mail-archive.com/[email protected]/msg39971.html The development team obviously has been in a hurry with other things. The fact that Krita is developed by voluntary programmers doesn't accelerate things.
The problem:
This is a 25 px wide bevel on a grey shape. The flat top has full light, the original color was darker. It works more like expected when the light altitude is higher than 45 degrees, but that light condition is not the wanted one, because it makes the flat top brightest.
Questioner's inner shadow workaround works well enough just in his case, but I do not recommend it. In sharp corners one can see an unwanted shadow border placement or one must leave the border fuzzy (=low choke).
The next workaround may be sometimes better: Select the shape (=Ctrl+click the layer icon in the layers panel). Make a shrinked selection and fill it with the original or other wanted color to a new paint layer. Here's my shrinked selection:
it's shrinked actually only 24 px. The 1 px difference ensures there's no fight just on the border of the flat top due antialiasing and math rounding errors.
A piece of the original is copied and pasted to the selection in a new layer:
The workaround doesn't generate anything as rich as Photoshop users have used to get with no effort. One cannot have at the same time bright highlights and deep shadows and the edge direction affects too lazily. The effect can be made richer by flattening the layer, applying curves and inserting a new Bevel&Emboss. The flat top area (made by copying the original with a shrinked selection) should be kept in a separate layer.
The workaround is not at all handy and even less, if one must apply the curves or the 2nd time the layer style with different settings. If one needs the layer styles, but must stay with freeware he can go to GIMP. By downloading a separate Layer Effects plugin (freeware) he gets the same effects as layer styles in Krita, but implemented to work much better. They are Python scripts which makes them slow, so do not expect Photoshop's slickness. But they work.
