Does the nextcloud desktop client change filename encoding?

Hi,

can it be possible, that the latest desktop client for windows changes the file name encoding at special characters like Ü etc.? I´ve identified that a program seems to change the file name encoding at special characters (utf8). Therefore another program cannot access this file any more, although the path and filename isn´t changed.

How can I ensure that nextcloud doesn´t change any encoding in filenames?