RU Server 220.127.116.11  Viewer 18.104.22.168 Windows 10 (1803)
If there is only group (without user from this group) autorized by security rights of an adress book, the adress book not synchronised for a user of this group. If we add autorisation for user(s) of the group explicitly, adress book synchronised well ! (see images attached to check settings).
Yes, "auto logon" is enabled, but, "auto logon" enabled or not, the problem still the same. Logoff / re-logon doesn't work either.
The relatable community thread indicated doesn't help me and conclusions are not clear… It seems doesn't works fine all the time (not like when user is Added explicitly).
One thing is sure, if you add explicitly the user (member of the group) in security rights of the adressbook, it works fine immediatly you valid the modification (therefore, it's not a RU server connection problem…). If you remove the user and valid the modification, logoff and re-logon, then synchronisation doesn't work again...
After some others tests, It seems you must restart the RU server after adressbook rights modifications ! If you do it and re-login, it seems works fine (but strange thing is if you add user explicitly, you have not to restart the RU server to changes take effect...).
I'm glad to hear you've figured out the issue. Unfortunately, we weren't able to reproduce it yet as it seems that the issue only occurs in some certain conditions. However, in the near future, we are planning to improve the server sign-in and synchronization processes anyway.
Please let us know if the issue reoccurs so we could proceed with the further troubleshooting.