Unable to find puppet_master template for <host> running Ubuntu 18.04

Problem:
Puppet wont provide the installation template for my hosts.
If I do a preview of all involved template from the web gui it all shows fine, but not when the host is trying to fetch it via the token url…

Expected outcome:
The rendered preseed template for this host.

Foreman and Proxy versions:
Foreman and foreman-proxt 1.20.2-1

Foreman and Proxy plugin versions:

Other relevant data:
This is the production log when the server want to fetch the provisioning data.

2019-05-21T10:54:16 [I|app|] Started GET "/unattended/puppet_master?token=1c268af5-351e-48e4-9eba-f3d0fe2919b5" for 10.46.28.217 at 2019-05-21 10:54:16 +0200
2019-05-21T10:54:16 [I|app|3b3f9] Processing by UnattendedController#host_template as TEXT
2019-05-21T10:54:16 [I|app|3b3f9]   Parameters: {"token"=>"1c268af5-351e-48e4-9eba-f3d0fe2919b5", "kind"=>"puppet_master"}
2019-05-21T10:54:17 [E|app|3b3f9] unable to find puppet_master template for _<my-real-fqdn-hostname>_ running Ubuntu 18.04
2019-05-21T10:54:17 [I|app|3b3f9]   Rendering text template
2019-05-21T10:54:17 [I|app|3b3f9]   Rendered text template (0.0ms)
2019-05-21T10:54:17 [I|app|3b3f9] Completed 404 Not Found in 711ms (Views: 0.6ms | ActiveRecord: 687.4ms)