Networkerror by Upload, Download works fine!

Hi guys,

Im using a Raspberry Pi as a Seafile Server over a NginX Webserver, it has a Domain over and a Lets Encrypt Certificate.

When Im donwloading a file from my server, it works fine, but if i want to upoad a file, there is always network error, from every browser (mozilla, chrome).

This is my NginX config:

If u need more information let me know!

Thank you for your advices.