If you use a subpath, the proxy_pass needs to include the URI; otherwise, it won’t work correctly. Therefore, the trailing slash must be removed in proxy_pass.

Using-a-Reverse-Proxy-with-Paperless-ngx.md

@@ -51,7 +51,7 @@ When using a domain subpath (e.g. `/paperless`), you need to set `PAPERLESS_FORC
         location /paperless/ {
 
             # Adjust host and port as required.
-            proxy_pass http://localhost:8000/;
+            proxy_pass http://localhost:8000;
         ...
 ```