Unable to connect with own Domain

Hello everyone,

I use a domain for my local network, the respective subdomains are managed by NGINX Proxy Manager. Generally everything works, I can also connect to my subdomain home.x.x without any problems. However, when I then enter the user and password, I only get

Unable to connect to Home Assistant.
Retrying in XX seconds…

If I use the IP:Port of HA it works without problems.

I use Cloudflare for my remote connection, which also works without any problems. I have therefore also entered the NPM in the config:

    - https://google.com
    - https://www.home-assistant.io
  ip_ban_enabled: true
  login_attempts_threshold: 3
  use_x_forwarded_for: true
    - # <- NGINX Proxy Manager

However, I still get the Retrying error.

Can someone help me here? Thanks in advance.

Got the same problem, no one an answer?