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

Riprodurre il problema eseguendo l'app Workflow Script su un file come Müller.pdf, quindi confrontare l'elaborazione tramite cron.php con il percorso previsto del logfile. Esaminare la gestione del percorso del file da parte dell'app e verificare che le dieresi vengano preservate nel percorso registrato; il problema è risolto quando il logfile contiene il nome file originale.