Question Regarding the use of Materials in Images:

Greetings!
When I add an Unlit shader Material created with ShaderGraph to my UI-Image, it looks like this in Game tab:

However, it appears normal in Scene.
If I switch the Shader to Lit, it displays correctly in Game, but strange shadows are added in Scene tab:

What could be causing this issue?
And, it seems that PostProcess does not affect UI?

PS. I need to draw some program-generated lines in UI using Images. How can I achieve this?

Thanks for your help。

 

I cant understand why it happend?