Approvers group does not save after adding it to the approval rules

Reproduction steps

Create groups:

• sc_approvals_test/{sc_approvals_subgroup,members/engineers} as sabinecarpenter
• Invite group sc_approvals_test/members/engineers as owner into sc_approvals_test/sc_approvals_subgroup
• Create project sc_approvals_test/sc_approvals_subgroup/test_project
• Invite user sabine.denk14dev_1 as owner into group sc_approvals_test
• Invite user sabine.denk14dev_2 as owner into group sc_approvals_test

Open a new browser and a new incognito window and login as user sabine.denk14dev_1 in one window and as user sabine.denk14dev_2 in the other one.

As user sabine.denk14dev_1, access: https://gitlab.com/sc_approvals_test/sc_approvals_subgroup/test_project/-/settings/merge_requests

And create approval rule sabine.denk14dev_1_test with approver sc_approvals_test/members/engineers // now refresh the browser: approvers will be empty

As sabinecarpenter, make sabine.denk14dev_2 direct owner in https://gitlab.com/groups/sc_approvals_test/members/engineers

As user sabine.denk14dev_2, access: https://gitlab.com/sc_approvals_test/sc_approvals_subgroup/test_project/-/settings/merge_requests

And create approval rule sabine.denk14dev_2_test with approver sc_approvals_test/members/engineers //

Refresh browser. Result: the two approvers show up. See screenshot below: