Import from .lib extension in startup.py

I’m trying to split the tabs in our extension into separate extensions.

I get an error that our Snippets module cannot be found by the startup.py script.

ImportError: No module named AVSnippets

Do I need to import it in a certain way, or is startup.py only able to import from a lib folder inside the extension it runs in?

The .lib extension is named the same as our main extension:
Company.extension
Company.lib

I assume the .lib extension might be loaded after the .extension?

Added info:
I don’t get the error on startup, only when reloading our extension or Enable/Disable our extensions.