Unable to share folder to federated instance's remote user group and as a consequence also it's members

Steps to reproduce

owncloud1 federates owncloud2,

owncloud2 has a user1
owncloud2 has a user group group1
user1 is member of group1 but neither an admin or group1 admin

owncloud1 federates owncloud2
owncloud1 has a new folder folder1
owncloud1 shares folder1 to owncloud2’s remote group group1

Expected behaviour

owncloud1 shares folder1 to owncloud2 group and as a result of that user1 having logged in is able to view the folder as shared by others

Actual behaviour

I get the error “Sharing {remote-group1-name} failed, could not find {remote-group1-name}@{owncloud2-web-url-with-https}, maybe the server is currently unreachable

Server configuration

Operating system:
Centos 7

Web server:
Apache HTTPD

MySQL version 5.6.36

PHP version:
version 7.0.19

ownCloud version: (see ownCloud admin page)
version 9.1.6

Updated from an older ownCloud or fresh install:

Where did you install ownCloud from:
zip file

Signing status (ownCloud 9.0 and above):

Login as admin user into your ownCloud and access 
paste the results into https://gist.github.com/ and puth the link here.

No errors have been found.

The content of config/config.php:

Log in to the web-UI with an administrator account and click on
'admin' -> 'Generate Config Report' -> 'Download ownCloud config report'
This report includes the config.php settings, the list of activated apps
and other details in a well sanitized form.


If you have access to your command line run e.g.:
sudo -u www-data php occ config:list system
from within your ownCloud installation folder

*ATTENTION:* Do not post your config.php file in public as is. Please use one of the above
methods whenever possible. Both, the generated reports from the web-ui and from occ config:list
consistently remove sensitive data. You still may want to review the report before sending.
If done manually then it is critical for your own privacy to dilligently
remove *all* host names, passwords, usernames, salts and other credentials before posting.
You should assume that attackers find such information and will use them against your systems.

List of activated apps:

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your ownCloud installation folder.

Are you using external storage, if yes which one: local/smb/sftp/...

Are you using encryption: yes/no

Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...

LDAP configuration (delete this part if not used)

With access to your command line run e.g.:
sudo -u www-data php occ ldap:show-config
from within your ownCloud installation folder

Without access to your command line download the data/owncloud.db to your local
computer or access your SQL server remotely and run the select query:
SELECT * FROM `oc_appconfig` WHERE `appid` = 'user_ldap';

Eventually replace sensitive data as the name/IP-address of your LDAP server or groups.

Client configuration

Safari for MacOS, Version 10.1.1 (12603.2.4)

Operating system:
MacOS Siera : 10.12.5 (16F73)


Web server error log

Insert your webserver log here

ownCloud log (data/owncloud.log)

Insert your ownCloud log here

Browser log

Insert your browser log here, this could for example include:

a) The javascript console log
b) The network log 
c) ...