Glass material messing up static mesh.

Hello, I’m new to working in unreal engine. My first game in fact. I ran into an issue with transparency. Especially with glass materials. Whenever I add a “translucent” material to my mesh, it completely destroys how it looks.

I have a bunch of buildings, and I want to add a translucent glass material to the windows. When I do this, some parts of my mesh disappears, and some parts look fractured into triangles.

I’ve attached two images.
In the first image, I used a simple reflective material for the window, which works fine for the buildings that have no interiors.

In the second image, the I’ve replaced the reflective material with Unreal’s stock glass material, and this is what happened to my model.

Would appreciate the help.
Thanks.