Cloudflare Access with Traefik

The Cf-Access-Jwt-Assertion header are not being sent to my Traefik webserver.

Could this have something to do with CNAME DNS?

My settings:
DNS A: v my-ip
CNAME: * mydomain

Access config:
subdomain:
domain: mydomain

Traefik app config:

I also use let’s encrypt and SSL full on Cloudflare.

When I try to reach an address subdomain.mydomain it won’t send the Cf-Access-Jwt-Assertion, but if I try to access mydomain it will redirect.