Chwala and external webdav not working except (GET) !

[Skale, Franz]

Hi,
before i file a bug report i wann know if anyone succeeded in getting 
external webav working with chwala.
My config.php snip:
$config['fileapi_drivers'] = array('webdav');

     // Pre-defined list of external storage sources.
     // Here admins can define sources which will be "mounted" into users 
folder tree /*
     $config['fileapi_sources'] = array(
	'Nextcloud' => array(
	    'driver'   => 'webdav',
	    'baseuri'  => 'https://nextcloud/remote.php/webdav/',
	    'username' => '%u',
	),
     );

I can view files which i already uploaded using a webdav client 
(curl(rfc), osx)
I cannot upload files via "save to cloud or in the roundcube 
filemanager), they have 0 bytes of size, then file will be created.
A RFC compilant upload using curl succeeds.

E.g:
curl --basic --user 'username:password' -v -T $PWD/test.jpg 
'https://nextcloud/remote.php/webdav/Documents/test.jpg'
It's a 6.MB file and the checksums are identical.
Since chwala should be rfc compilant, what's the problem ?

Thanks in advance

Franz

Debug during upload:
*   Trying xxx.xx.xxx.xx...
* TCP_NODELAY set
* Connected to nextcloud (xxx.xx.xxx.xx) port 443 (#0)
* ALPN, offering http/1.1
* Cipher selection: 
ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /usr/local/etc/openssl/cert.pem
   CApath: /usr/local/etc/openssl/certs
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* NPN, negotiated HTTP1.1
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
* TLSv1.2 (OUT), TLS handshake, Unknown (67):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN, server did not agree to a protocol
* Server certificate:
*  subject: CN=nextcloud
*  start date: Nov 22 11:02:22 2017 GMT
*  expire date: Feb 20 11:02:22 2018 GMT
*  subjectAltName: host "nextcloud" matched cert's "nextcloud"
*  issuer: C=US; O=Let's Encrypt; CN=Let's Encrypt Authority X3
*  SSL certificate verify ok.
* Server auth using Basic with user 'user at example.com'
> PUT /remote.php/webdav/Documents/test.jpg HTTP/1.1
> Host: nextcloud
> Authorization: Basic xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> User-Agent: curl/7.56.1
> Accept: */*
> Content-Length: 7042920
> Expect: 100-continue
> 
< HTTP/1.1 100 Continue
* We are completely uploaded and fine
< HTTP/1.1 201 Created
< Server: nginx
< Date: Wed, 22 Nov 2017 13:25:10 GMT
< Content-Type: text/html; charset=UTF-8
< Content-Length: 0
< Connection: keep-alive
< X-Powered-By: PHP/7.1.11
< Expires: Thu, 19 Nov 1981 08:52:00 GMT
< Cache-Control: no-store, no-cache, must-revalidate
< Pragma: no-cache
< Set-Cookie: 
oc_sessionPassphrase=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx; 
path=/; secure; HttpOnly
< X-Frame-Options: SAMEORIGIN
< Set-Cookie: __Host-nc_sameSiteCookielax=true; path=/; httponly;secure; 
expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=lax
< Set-Cookie: __Host-nc_sameSiteCookiestrict=true; path=/; 
httponly;secure; expires=Fri, 31-Dec-2100 23:59:59 GMT; SameSite=strict
< Content-Security-Policy: default-src 'none';
< Set-Cookie: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx; path=/; secure; 
HttpOnly
< Set-Cookie: cookie_test=test; expires=Wed, 22-Nov-2017 14:25:09 GMT; 
Max-Age=3600
< OC-FileId: xxxxxxxxxxxxxxxxxxxx
< ETag: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
< OC-ETag: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
< Strict-Transport-Security: max-age=31536000; includeSubDomains
< X-Content-Type-Options: nosniff
< X-XSS-Protection: 1; mode=block
< X-Robots-Tag: none
< X-Download-Options: noopen
< X-Permitted-Cross-Domain-Policies: none
<
* Connection #0 to host nextcloud left intact