Deploying host cloudinit-based via foreman-proxy fails after upgrade to foreman 2.3

Problem:
Cloudinit-based deployment via foreman-proxy fails (works via foreman directly though)
Curling user-data from foreman-proxy returns There was an error rendering the CloudInit default demo template: undefined method full_path for nil:NilClass

Expected outcome:
Deployment successful (as via foreman)
Curling user-data from foreman-proxy returns cloudinit-template (as curling from foreman does)

Foreman and Proxy versions:
2.3.5 (both)
Foreman and Proxy plugin versions:

Distribution and version:
CentOS 7
Other relevant data:
Hi,
I am trying to deploy a server image-based using cloudinit-templates via foreman-proxy. This used to work before foreman version 2.3 (the foreman-proxy had to added to the parameter remote_adress in addition to foreman server though). After upgrading apparently the parameter remote_adress no longer exists in this version and seems to have been replaced by the setting “trusted hosts”.
I tried to set the trusted hosts in the katello-answers.yaml on the foreman and foreman-proxy-content-answers.yaml on the foreman proxy (with subsequently running foreman-installer → value is being correctly set in setting.yml), but deployment remains impossible, as the proxy returns an internal server error 500.
When trying to curl the user-data this only works for foreman, the foreman-proxy returns There was an error rendering the CloudInit default demo template: undefined method 'full_path' for nil:NilClass
This has not been changed by the trusted hosts setting.
Before upgrading to 2.3 the proxy correctly returned the cloudinit-template (as it still does for foreman) and the host could be deployed.
Can possibly any one tell me the correct setting to deploy cloudinit-based via foreman proxy? Thanks!