[Install help] Connectivity issue: paperless-ai to -ngx API behind Traefik

[snl-r]

My paperless-ai (/setup) does not connect to paperless-ngx. This is on a dedicated remote server. NGX is running fine, behind Traefik (Pangolin). In NGX, I created an API key for the user and provided URL/user/key on the -ai /setup page. Error message in the GUI is "Failed to initialize connection to Paperless-ngx. Please check URL and Token." and docker logs -f paperless-ai = "[ERROR] Failed to initialize with credentials: connect ECONNREFUSED myIP:443" ... this looks like a CORS error maybe, since the creds are definitely ok, but in NGX docker_compose.env I already set PAPERLESS_URL=myURL, and also PAPERLESS_CSRF_TRUSTED_ORIGINS and PAPERLESS_ALLOWED_HOSTS and PAPERLESS_CORS_ALLOWED_HOSTS each to myUrl,aiURL,llmURL and restarted - the error remains the same. Pangolin does add SSO, and I added some rules (always allow from ai domain), and disabling SSO alltogether makes no difference either. What else could I be missing?

[snl-r]

Am I supposed to NOT do this via the exposed URLs, but docker-to-docker instead? All three, Pangolin (Traefik), paperless-ngx, and paperless-ai are on the same VM. However, I'm looking at https://ai.mydomain.com/setup and local URIs don't work out either.

With local/internal IPs in the /setup form, and also adding them in CSRF/CORS params in paperless-ngx' docker-compose.env, the error in docker logs -f paperless-ai changes to "[ERROR] Failed to initialize with credentials: read ECONNRESET"