Download from WebDAV is sooooo slow (13.0.2.1)

Hi there,
I’m connected to my nextcloud install from WebDAV (web-installer). The same file will be downloaded at 8.3K/sec from WebDAV and 25MB/sec from ftp… with the same connection (Fiber). This problem persist since version 13.
Someone else had the same problem and solved it?
Thanks for your help