Translucent material changes color when playing in-game

Hello everyone, first of all sorry for my english!

I have a problem with a dirty glass material that changes the color of dirty areas when I use the play in viewport preview.

When I build the lighting, the dirt color appear white in the glass as intended, but when i go in-game the dirt turns to black! If I return again to edit mode, the colors return to normal (white, in this case)

Here is a picture for a better understanding of my problem:

Now a picture of my material setup

:

I’m using a technique that I came up with, where the window is composed of two separated materials, one for each side of a two face plane. One side I’m using a wet glass material created separately for simulating raindrops, and on the other side, this troublesome dirty glass material.

One more thing: Whenever I make some changes in the material and apply, the dirt colors appear as black like in game preview. But, if I build the lighting the desired white dirt color returns, but, as already mentioned, only while I’m working in edit mode.

I’m starting to lose some hair here… hahaha

Sorry for my grammar mistakes and I’ll be eargely waiting for any answer! Thanks for your help!