Depth Fade with MSAA and Forward Shading

Found this strange outline effect when using Depth Fade in opacity
The outline can be fixed with if expression, but this is still a strange bug

Happens only with Forward Shading + MSAA

Hi @Bargest2 , thanks for sharing! I know it has been a while, but could you briefly explain or show how to use if expression to remove that bug?
Thanks in advance!