500 error when trying to create a new note

Please make a clear and concise description of what the bug is.

When I try to create a new Note in the web interface, I get "Creating new note has failed. HTTP 500 (Error)"
The weird thing is, when I refresh the page, the new note is there just fine.

The bigger issue is, creating new notes just doesn't work at all from the Android app.

Not sure if it makes a difference, but I am trying this from an external network configured for remote access via a Cloudflare Tunnel. Currently unable to try it on the local network.
*Can now confirm everything is the same over the local network

-->

Steps to reproduce

1. Click "+New Note"

Expected behaviour

It should create a new note with no issue

Actual behaviour

On desktop web app, it creates the new note but says it can't. On Android app, it just doesn't create the note. Instead, it creates a bunch of empty duplicates with the same name followed by (1,2,3...).

Screenshots

Server

Please complete the following information.

• Notes app version: 6.0.1
• Nextcloud version: 33.0.5
• OS: MacOS and Android

Client

Please complete the following information.

• Browser (incl. version): Firefox 152.0.6
• OS: MacOS Tahoe
• Android: Nextcloud Notes 34.0.0

Reproduce note creation from the web interface and Android app using both the remote and local network conditions described. Compare the reported HTTP 500, successful-but-failed web creation, and Android duplicate behavior; done means creating one note succeeds without an error or empty duplicates in both clients.