CURL http time out too short

With Kodi 17 beta 6 I have problems accessing my https server.
The server isn’t the fastest (Raspi with 2 USB HDDs) so the response time is not that great but the actual file delivery works well for videos. So I’m getting random timeouts accessing my library.
Accessing it via “files” and playing files from there works so a connection is possible. So is there a possibility to increase the wait for a HTTPS response? I know it’s a timeout because of this in the log:

Code:
11:09:04.564 T:10188   ERROR: CCurlFile::FillBuffer - Failed: Timeout was reached(28)
11:09:04.565 T:10188   ERROR: CCurlFile::Open failed with code 0 for https://USERNAME:[email protected]:443/serien/
11:09:04.565 T:10188   ERROR: XFILE::CHTTPDirectory::GetDirectory - Unable to get http directory (https://USERNAME:[email protected]:443/serien/)
11:09:04.573 T:10580   ERROR: XFILE::CDirectory::GetDirectory - Error getting https://USERNAME:[email protected]:443/serien/
11:09:04.577 T:10580   ERROR: CGUIMediaWindow::GetDirectory(https://USERNAME:[email protected]:443/serien/) failed

1. Version of Kodi: Kodi 17 beta 6
2. Windows 10 1607
3. CPU/Architecture: Intel Xeon 1230 v3 / Haswell
4. RAM amount: 32GB
5. see above
6. Webserver: Raspi3 + nginx 1.10

The debug log addon doesn’t seem to work for me but I can upload a full log if desired.