Groups defined in CODEOWNERS file are only optional approvers?

Summary

There are two groups: Group_A and Group_B. The former contains 20 members with 'developer' access level. The latter has 10 members defined with develop permission as-is and the Group_A added with developer max access level.

There is a project Project_1 inside the Group_B with protected master branch and Code owner approval option being enabled. The project contains CODEOWNERS file with the following content:

[Maintainer]
* @User1

[Documentation]
/docs/ @Group_A

When an MR inside the project is created with changed files inside /docs/ directory, the Group_A members are added to the MR only as optional approvers but not mandatory ones. It seems to be unexpected behaviour and thus to be an issue.

Steps to reproduce

• Create two groups: Group_A and Group_B
• Add some users to both of them with developer access level
• Create new project Project_1 inside Group_B
• Make the master branch of the project to be protected one and enable Code owner approval option.
• Add one of the Group_B members to the project with maintainer permission.
• Add Group_A as a whole to Group_B with developer maximum access level.
• Create docs directory and readme.md file inside to the project.
• Create CODEOWNERS with the following content:

[Maintainer]
* @User1

[Documentation]
/docs/ @Group_A

• Create new GIT branch docs-1 from master branch
• Make some changes in docs/readme.md file inside docs-1 branch
• Create new MR from docs-1 to master branch

What is the current bug behavior?

The Group_A members defined via CODEOWNERS file are added as optional approvers to MRs

What is the expected correct behavior?

Any merge request HAS TO BE APPROVED by at least ONE of the each and every group mentioned in the CODEOWNERS file.

Relevant logs and/or screenshots