Settings not saved when using CWA on books.myserver.com but saved when loading CWA on local IP

[j-peeters]

Hi, I have installed CWA today and made it accessible to the internet via Nginx Proxy Manager and Authelia as auth manager.
I can access CWA via Authelia (SSO).

A few things don't work though and hopefull any of you know what can cause this and how to solve it. All the things below work when done from local IP: 192.169.178:10:8083 but not when loading CWA from books.myserver.com after having logged in with Authelia via Nginx Proxy Manager. Cloudflare does my DNS.

I have added 'books.myserver.com.nl,auth.myserver.com,192.168.178.10' to trusted hosts in CWA.

• Fetching Metadata doesn't conclude. I don't see any fetched data show up. Data shows up instantly on local IP
• Uploading a book doesn't show it's finished (it does upload, I can see it in Calibre)
• Saving settings doesn't work, but settings are saved when accessed from local IP.

I realize that this might also have something to do with configuration of either NPM or Authelia, but I thought maybe someone has configured it like me and knows what needs to be done different. Thanks for any ideas and possible solutions.