Native Render DLL doesn't work when imported through package?

I have a native dll that makes rendering calls. It works just fine when put in the Assets folder. But if I put it in a package and try to import it through that, either via git url or on my local disk, it doesn't work.

The package does not output any errors, in the console looks like it should work, but doesn't.

There are two dll's in this package, one makes native rendering calls, the other doesn't. Only the one which makes native rendering calls does not work.

Is there some extra condition I should be aware of if trying to package a native dll that makes rendering calls?