`master` branch inaccessible to `developer` group?

I’ve imported a number projects and created a group called “shared” that I’m using to assign initial permissions to projects that were shared by the entire company previously.

On one problem project I have the shared group assigned as having Developer permissions / role (under the Project Name -> Settings -> Members area). When someone attempts to push to the master branch of this project in GitLab, it is blocking the user from committing a direct push to this branch; talking about how the master branch is protected:

You are not allowed to push code to protected branches on this project.

Why might this be happening? Do I need to change some additional permissions that I’ve missed for this project? Or is there a “protected” status that needs to be changed somewhere?

So I found out that this is actually a function of the system to attempt to protect the master branch via forcing committers to make merge / pull requests.

Manual: https://docs.gitlab.com/ee/user/project/protected_branches.html#configuring-protected-branches