Zammad: No users on "Users mamagement"

Infos:

• Used Zammad version: 2.8.0-1549301377
• Installation method (source, package, ..): package
• Operating system: CentOS 7
• Database + version:
• Elasticsearch version: 5.6.14-1
• Browser + version: Firefox, Chrome, ...

Expected behavior:

• Users show up in the "Users Management" section

Actual behavior:

• The "Users Management" section is empty.
  Adding new users seems to work, but they do not show up in the list.
  Listing users on the rails console works fine.
  It seems to be just a cosmetic issue with on the web interface

/var/log/zammad/production.log looks fine.
Whenever I click on one of the roles in "Users Management" The requests are processed without error (return 200).

The only error I can see is at:

Payload size: 0M
E, [2019-02-05T17:44:59.430366 #5417-47218874103620] ERROR -- :   
2019-02-05T17:44:59+0100: [Worker(host:zammad.local pid:5417)] Job
BackgroundJobSearchIndex (id=16) FAILED (3 prior attempts) with RuntimeError: Unable 
to process POST request to elasticsearch URL 'http://localhost:9200/zammad_production
/User/3?pipeline=zammad895142058248'. Check the response and payload for detailed 
information: 

Response:
#<UserAgent::Result:0x00007f5da9857a38 @success=false, @body="{\"error
\":{\"root_cause\":[{\"type\":\"illegal_argument_exception\",\"reason\":\"pipeline with id 
[zammad895142058248] does not exist\"}],\"type\":\"illegal_argument_exception
\",\"reason\":\"pipeline with id [zammad895142058248] does not exist\"},\"status\":400}", 
@data=nil, @code="400", @content_type=nil, @error="Client Error: 
#<Net::HTTPBadRequest 400 Bad Request readbody=true>!">

Steps to reproduce the behavior:

• Update Zammad from an oder version or install it from scratch.

The issue (or an equivalent one), seems to be common:
https://community.zammad.org/t/no-users-on-users-management/1108/2

Steps to reproduce the issue accurately (on a CentOS 7 KVM machine):

yum -y update
yum -y install epel-release wget
wget -O /etc/yum.repos.d/zammad.repo https://dl.packager.io/srv/zammad/zammad/stable/installer/el/7.repo
rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch

echo "[elasticsearch-5.x]
name=Elasticsearch repository for 5.x packages
baseurl=https://artifacts.elastic.co/packages/5.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md"| tee /etc/yum.repos.d/elasticsearch-5.x.repo

yum install -y java-1.8.0-openjdk-devel
yum install -y elasticsearch

echo "JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:bin/java::")" | sudo tee -a /etc/profile
source /etc/profile
## I am behind a corporate proxy, so I need to preceed the elasticsearch command with the java environment variables
ES_JAVA_OPTS="-Dhttps.proxyHost=MY_HTTP_PROXY.COM -Dhttps.proxyPort=8080" /usr/share/elasticsearch/bin/elasticsearch-plugin install mapper-attachments --batch

systemctl restart elasticsearch
systemctl enable elasticsearch

# SELinux / Firewall
setsebool httpd_can_network_connect on -P
firewall-cmd --zone=public --add-service=http --permanent
firewall-cmd --zone=public --add-service=https --permanent
firewall-cmd --reload

# For some reason the default nginx config overlaps with conf.d/zammad.conf
sed -i '/^    server {/,+19 s/^/#/' /etc/nginx/nginx.conf
systemctl restart nginx

zammad run rails r "Setting.set('es_url', 'http://localhost:9200')"
zammad run rake searchindex:rebuild
zammad run rails r "Setting.set('es_user', 'elasticsearch')"
zammad run rails r "Setting.set('es_password', 'zammad')"

After that, visit the web interface, create a new environment, log in, and that's it: No users in "Users Management".

Yes I'm sure this is a bug and no feature request or a general question.