submodules nested in folders not linked correctly

We currently have serveral projects which are using other projects as submodules. All of them are hosted in the same gitlab instance. Thats why we have used relative paths within .gitmodules like:

[submodule "test/repo"]
  path = test/repo
  url = ../../test/repo.git
[submodule "test/test2/repo"]
  path = test/test2/repo2
  url = ../../test/test2/repo.git

The submodules are arranged in folders within each project. The folderstructure equals the submodule path:

project\test\repo.git
project\test\test2\repo.git

Within the webUI the following pages each list the submodule project

http://localhost:8080/project/test/ http://localhost:8080/project/test/test2/

When following the submodule project links, the first one mentioned above resolves perfectly to http://localhost:8080/test/repo.git, while the second one resolves to http://localhost:8080/project/tree/test/test2/repo.git.

Looking into the html-code of each page, the first href value is "/test/repo.git" while the second one is "../../test/test2/repo.git".