Multiple custom domains for different stages in eu-central-1 region

I am building my first simple serverless one function application, which needs to support different domains for the different stages (dev, stage, prod) and should be hosted in the AWS eu-central-1 region.
I used the serverless-domain-manager plugin to get the functionality. It works fine, as long I create the domain in the us-east-1 region, but I can not get it to work in the eu-central-1 region.
I have done short writeup here

Somebody a new idea? I ran out of ideas to fix this…
Thanks in advance!