Lightmaps disappear after reloading level

Hello, I bake lightmaps, close and reload the level, and lightmaps appear to either be fullbright or gone completely; with the only thing causing any shadowing to happen being the dynamic cascade shadows.

What is causing this to happen and/or how can I prevent this from happening and fix the issue?

Here is a screenshot of theproblem (close to camera dynamic cascade shadows, distant from camera fullbright baked lighting):

Note: lightmap UVs are correct, texel density is adequate, lighting behaves as expected after baking, issue appears only when closing and re-opening the level.
Are lightmaps somehow not being saved or applied correctly?

I second that!