Owncloud Upgrade and Reverse Proxy Settings

Configuration

Nextcloud Server: 31.0.5
Operating system: Debian 12
Web server: Apache 2.4.62
Reverse proxy: HAProxy 0.64 (haproxy-devel package on Netgate 6100)
PHP version: 8.3.21

Issue:

I walked through the simple (but painful) process of migrating from my Owncloud 10.15 to NextCloud. Once I hit version 28 or so I was no longer able to see Security and Setup details if I accessed that page via the reverse proxy doing SSL offloading. If i accessed that page using http directly then it displays just file.

Would appreciate some help figuring out what i am missing.

Accessing directly:

Accessing via the reverse proxy:

HA Proxy Configuration

Frontend

Backend

Looking in the Apache2 error logs, I see this:

[Tue Jun 03 22:12:35.831050 2025] [access_compat:error] [pid 3399:tid 3399] [client 192.168.0.254:34980] AH01797: client denied by server configuration: /var/www/owncloud/data/.ncdata