How do I fix materials that look different packaged from in-editor?

I’m having trouble understanding the discrepancies between how some materials look when seen in-editor vs. in a packaged executable file.

I’ve made a simple bubble material using the blueprint PBR material editor in the engine. Below I have images of the bubble material blueprint and how it’s viewed in the blueprint editor, respectively.


When testing the game in-editor, the material looks fine.

However, when packaged as an executable to lend to testers, it appears very different.

Does anyone know what’s going wrong with this? Or has anyone else had a similar problem with projects looking different in editor vs packaged?