Well, I understand that even if the issue is resolved, it will be too late. But I want to deal with this issue for the future. Now I am actively uploading files to my server. Many small files are very convenient to upload via WebDAV. I would be happy to upload all the files via WebDAV, but the difficulty arose. I noticed that files larger than 500MB are not transferred via WebDAV. What is the reason for this?
You can use the Flow Upload App: https://apps.nextcloud.com/apps/flowupload
Thanks, great alternative!