Fixed most broken clients (macOS app, Chromium on macOS and Android) by disabling the CSP headers in the nginx SSL reverse proxy:
#add_header Content-Security-Policy "object-src 'none'; base-uri 'none'; require-trusted-types-for 'script'; frame-ancestors 'self';";
#add_header Content-Security-Policy "frame-ancestors 'self';";
However, the Android app v2.12.1 (Build 6000505) is still unable to connect to my server when entering https://REDACTED.de:444 as Server-URL. I can access Mattermost from the affected phone just fine using Firefox or Chromium. When the app tries to connect to the server, this is the only line printed to the log:
127.0.0.1 - - [01/Feb/2024:23:26:12 +0100] "GET / HTTP/1.1" 200 1253 "" "okhttp/4.12.0" 2.83
The Android app also cannot connect via http:// without encryption using port 82. I’ve tested this on two Android phones (Google Pixel 6 Pro and Pixel 6a).
Has the Android app been tested with non-standard ports? Is there any way to get more info from the app why it cannot connect?