App removes Umlauts

Hello,
I have a Script that processes various files but every time a Filepath contains a Umlaut (äöüÜÖÄ) the App removes them from the Path and the Script fails. Wich is weird because i have a seperate Nextcloud server (but a older version) for Testing where the App does not remove the Umlauts and the Script works perfectly.

I just recently setup the Nextcloud where i encounter this Problem. Is it possible that i made some mistakes in the setup Process that causes this to happen? I searched for hours but could not find documentation on this problem.

I dont know if its a bug for newer versions or if im just too dumb to see my error but help would be very appreciated.

Steps to reproduce

1. Setup Workflow_Script to echo filepath to logfile
2. do smth to File with Umlauts (e.g. Müller.pdf)
3. wait for cron.php or execute
4. Open logfile

Expected behaviour

path in logfile is,
some/file/called/müller.pdf

Actual behaviour

path in logfile is,
some/file/called/mller.pdf

Workflow Script app

**Workflow Script app version: 1.7.0

Server configuration

Operating system: Ubuntu

Web server: Apache

Database: Maria

**Nextcloud Version: 22.2.0

Reproduzca el problema ejecutando la aplicación Workflow Script con un archivo como Müller.pdf y, a continuación, compare el procesamiento mediante cron.php con la ruta esperada del logfile. Inspeccione el manejo de la ruta del archivo por parte de la aplicación y verifique que las diéresis se conserven en la ruta registrada; el problema está solucionado cuando el logfile contiene el nombre de archivo original.