We have a self-hosted gitlab-ee instance (15.5.4-ee.0 amd64). Some of our repositories use submodules. All these submodules projects are local, i.e. hosted on the same gitlab-ee instance.
For the repositories, I created a while ago (a month ago), the “compare” options on any merge requests pages give me a submodule diff option (described here: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/37740). Recently, I created a new repo that uses submodules. I don’t get any submodule diff option for the merge requests in this new repo. The old and the new hash are just highlighted in red and green, respectively. The submodule compare option is a heavily useful tool for our enterprise.
Is this a per-repo configuration? I tried finding the option in Repository settings and documentation but couldn’t find anything relevant. Any pointers would be helpful.