Not sure if this is related to mkdocs, mkdocstrings, or pytkdocs.
When using content tabs with the Tabbed extension:

markdown_extensions:
  - pymdownx.tabbed

within different module docstrings, which are rendered on the same page, their IDs are regenerated and the following content tabs link to the first content tabs when clicked.

To reproduce, add a content tab block in the docstring of two modules:

=== "Tab1"
   some content

=== "Tab2"
   some content2

and then add the modules in the same markdown:

::: module1

::: module2