Request failed: internal server error (500)

Expected behaviour

log in to the iOS app with error

Actual behaviour

Receive error message Request failed: internal server error (500)

Steps to reproduce

1. Open the Nextcloud app for iOS
2. login to your account using the old authorization method
3. get error 500

iOS version

13

App version

2.25.9

Operating system:
CentOS 6

Web server:
apache 2.2.15 | nginx 1.16.1 (reverse proxy)

Database:
PG10

PHP version:
7.2

Nextcloud version: (see Nextcloud admin page)
17.0.3

The official Nextcloud app for iOS is installed. after logging in with the old authorization method, the error “Request failed: internal server error (500)” is displayed.
it appears once upon the first authorization. after which the error window disappears and the application works as usual.

I use the old authorization method because I can’t use the standard one because I have nginx with reverse proxies and balancers. when I try to log in by default, I get the error “csrf check failed”. the option with “overwriteprotocol => https” helps with this error “csrf …”, but it doesn’t suit me because of the limitations of the infrastructure.

No source file or test is identified in the report; start by reproducing the first-login failure in the iOS app's old authorization flow against the listed Nextcloud, reverse-proxy, PHP, and PostgreSQL setup. Done means the initial authorization no longer returns HTTP 500, while subsequent login behavior is verified.