Bug Occlusion Culling, some assets in camera view hidden.

I'm taking over a project from the previous employee.
This scene has problems where a few assets are being occluded when the camera is looking at them, while other objects are fine. This only happens in Playmode, during the visualization in the Editor the Occl Culling seems fine.

- I tried making a boundary box.
- I checked and unchecked anything in the Static dropdown to see if it made a difference.
- I checked if some things needed to be checked upon import/export, perhaps those problematic assets missed a few checkmarks. Nope.
- In fact, I tried to reimport the problematic asset into the project again, but it still disappears in Play Mode.
- I noticed that the scene was building using several old scenes, so maybe the objects that do work fine with occlusion culling were of a different scene and the problematic ones from a different one. Don't know why that should be a problem though.