Widget loses textures after packaging

Hi there, I’ve been encountering issues with widgets in UE4.20.

Mainly after packaging the game to be tested, any widget buttons lose the image texture given to them and just appear as colored squares.

Here is what it’s supposed to look like and what it looks like in the editor.

Here is what it looks like in a packaged build

I’ve heard from a friend that you have to manually set the widget styles for each button but I find this very hard to test and verify, has anyone found a different fix?

I can’t upgrade to 4.21 either to test if that works because an important marketplace plugin we use doesn’t support that engine version yet.

If anyone knows of a fix, I’d be very grateful :p.