403 Forbidden on Android using Nextcloud App

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Steps to reproduce

1. On Android login using the Nextcloud App

Expected behaviour

The Apache server that hosts the IDP should redirect to my login form

Actual behaviour

Apache throws an 403 error. However this only occurs when logging in with the Android app. Using the mobile browser or the desktop app, all works fine.
Apache logs the following error

[rewrite:error] [pid 1168:tid 1168] [client XXX:33946] AH10508: Unsafe URL with %3f URL rewritten without UnsafeAllow3F

This seems to be related to https://stackoverflow.com/questions/78729429/403-forbidden-when-url-contains-get-with-encoded-question-mark-unsafeallow3f

Server configuration

Web server: Apache 2.4.62 with Nginx Proxy

Start by reproducing the Android app login against Apache 2.4.62 behind the Nginx proxy and inspect the rewrite error containing UnsafeAllow3F. Determine why the Android request is rejected while browser and desktop logins succeed; done means the Android login reaches the IDP login form without a 403.