server-info.action unavailable for mobile app

[Michael Levec]

Basically, I am running into this issue:

https://confluence.atlassian.com/confkb/can-t-check-compatibility-error-in-the-confluence-server-mobile-app-943523933.html

The KB tells me to make server-info.action available to the mobile app. But if I try that url from a browser, like https://<my base url as i usually hit the landing page>/server-info.action just results in a simple 404 error.

Confluence mobile app is enabled

Confluence Server is version 6.15.9

Reverse Proxy is Apache 2.4 and is properly configured to map the base url to confluence (runs smoothly for months now)

Certificate is Let's Encrypt.

There is no firewall or vpn inbetween, as the KB article suggests.I also read https://confluence.atlassian.com/doc/confluence-mobile-284365706.html but I still do not see it.

What are the steps I have to take to make this work? What am I overlooking?

Thanks in advance for any reply.