Gitlab merges automatically on behalf of Developer when a merge conflict is resolved

Got reported from one of the Dev’s Team member about their issue on that approach :

  1. Repository with master and production(protected) branch
  2. Master 2 PROD Merge request => MR conflict appears
  3. Create feature branch from production and resolve the conflict. After that create feature → prod MR
  4. After merging 3) step, 2) is automatically merged without even an approval.

is this is bug or the approach should be different :

  • Create a branch from master B1
  • Merge Production branch to B1
  • Resolve conflicts and commit them to B1
  • Merge B1 to Master
  • Conflicts resolved

any advices in this case ? thanks lot