@bastian-src sorry for the delay.
In this network is no DHCP relay/server available. I am not sure if we can use pxe in this case.
Nevertheless, I changed the PXE loader from ‘none’ to ‘PXELinux BIOS’
Now I am receiving the following error:
HTTP://<MYPUPPETSERVER>/unattended/iPXE... No such file or directory.
2022-12-06T10:39:25 8edda413 [I] Started POST /puppet/ca/autosign/<myhost> 2022-12-06T10:39:25 8edda413 [I] Finished POST /puppet/ca/autosign/<myhost> with 200 (0.63 ms)