Hello, there are issues with viewport in Material Mode (!!) making my model very noisy. The textures are fine and this problem appeared after Blender’s update… Is there any solution?
(Changing viewport samples on both engines didn’t help)
That looks like soft shadows…
Note that what you call ‘Material Mode’, is simply Eevee… So you could just disable ‘Scene Lights’ and set some HDR in the viewport shading properties, if you don’t have a World set.
Welcome 
…
also the Material Preview is “a very simple preview” to get a general idea… a better preview might be Rendered with less samples…
Update, well
I decided to move on previous version
Here is comprassion with the same preferences
4.2.1 (left) and 4.1. (right)
I hope it will be fixed in newest versions
Yepp… seems to be Eevee Next is better in some areas and also slower yet and has some higups (maybe it’s a new sample settings IDK… ).