Thanks again for your time!
Actually, I have similar issues in other apps. Sometimes when I’m writing notices in Zotero the pragraph i just typed disappears. In Zotero this doesn’t lead to a file-corruption, though. My Windows One Note-app also occasionally shuts itself down (also without corruption). Does this indicate that there is a hardware issue/ general issue?
No other service is accessing the file and I have only one hard drive. As a cloud storage I’m using a nextcloud-installtion run by my University (tubcloud).