Response status "403 Forbidden" when uploading artifacts

Summary

When artifacts are enabled, we encounter the following error:

ERROR: Uploading artifacts to coordinator... forbidden  id=5843 responseStatus=403 Forbidden status=403 Forbidden token=****
FATAL: permission denied 

Steps to reproduce

.gitlab-ci.yml

prebuild-frontend:
  image: "node:10"
  stage: prebuild
  script:
    - cd client/
    - npm install
    - *version
    - sed "s/0.0.0/$VERSION/" -i package.json
    - npm run build

  artifacts:
    paths:
      - ./client/dist
    expire_in: 1 day

  # need to run it always
  only:
    refs:
      - merge_requests
      - master
      - tags
  cache:
    key: node-modules
    paths:
      - ./node_modules/**/*
      - /root/.npm/**/*

Actual behavior

All jobs having artifacts are failing with the described error.

Expected behavior

Artifacts should get uploaded properly.

Relevant logs and/or screenshots

job log

Uploading artifacts...
 ./client/dist: found 1460 matching files           
 ERROR: Uploading artifacts to coordinator... forbidden  id=5843 responseStatus=403 Forbidden status=403 Forbidden token=*****
 FATAL: permission denied                           
 ERROR: Job failed: exit code 1

Environment description

Using custom installation from source.

Gitlab: 12.7.2

Workhorse: 8.19.0

Gitaly: 1.83.0

NGINX: 1.16.1-r1

Docker: 18.09.9, build 039a7df

config.toml contents

concurrent = 4
check_interval = 0

[[runners]]
  name = "Gitlab CI Docker Runner (mint.lab.awesome-it.de)"
  url = "https://gitlab.********"
  token = "**********"
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "docker:git"
    privileged = false
    disable_cache = false
    shm_size = 0   

Used GitLab Runner version

$ gitlab-runner-v12.7.1 --version
Version:      12.7.1
Git revision: 003fe500
Git branch:   12-7-stable
GO version:   go1.13.5
Built:        2020-01-23T09:08:54+0000
OS/Arch:      linux/amd64