pixelated shadow of moving object on translucent material

Hi, I’m trying to move an object over a translucent surface(water in this case) and the shadow is pixelated when I move the object(it flickers), here is the video :Video

translucent materials info:

  1. Material Domain: Surface
  2. Blend Mode: Translucent
  3. Shading Model: Default Lit(Two Sided)
  4. LightMode: Surface TranslucencyVolume(when I change it to SurfaceForwardShading I get a very sharp shadow and the problem goes away but that’s not an option for me, also I don’t have this problem on non-translucent surfaces).

Things I have tried so far:

  1. Changing the Anti-Aliasing Method from AA to other ones and didn’t work,
  2. Setting Responsive AA in the material itself and it didn’t work.
  3. using r.Shadow.MaxResolution 2048 command to increase the resolution of shadow, but I could not understand the difference between 2048 and 64, it seems like it does not work!

Note that I’m using Distance Field Shadows as well

What can cause this problem?

It is correct operation of translucency lighting volume and its low res shadow.

Is there anything I can do to soften the shadow here?