HomeAssistant setup with AWS Lambda

Hi. I am currently trying to connect my home assistant with alexa. I did everything according to Amazon Alexa Custom Skill - Home Assistant and it is working with a long lived token and in debug. But without debug and the token I get an ssl error

SSLError(CertificateError("hostname 'www.XXX.duckdns.org' doesn't match 'XXX.duckdns.org'"))': /api/alexa/smart_home

This is correct since the domain of the generated ssl certificated of the duckdns addon isxxx.duckdns.org.

What is wrong with my setup? Does the generated ssl certificate not work with this setup?