Outlook sync stopped all of the sudden

Hello, 

I hope some experienced a similar issue with the Outlook. It stopped any communication with the Icewarp server. No emails are coming at all. I upgrade IceWarp to the latest version (server) and IW Outlook app as well. By forcing synchronization of the messages or folders, the icon will flash for a second and nothing happens. Outlook is not in an offline mode, IW plug-in works otherwise fine. Nothing changed on the computer itself. I have created new Outlook profile and this inbound /outbound flow works fine. Problem is that not all folders synchronized. There are number of sub folders in the previous Outlook profile that are not shown in the new one. That's after allowing to sync up over night with the server and station on the same LAN. Only a single user experiences that. Now, webmail does not seem to have all folders either, only the previous Outlook profile, so I need to preserve it. Not sure why those folders did not get pushed out to the server. Server certificate seems to be fine. Again, no one else seems to be complaining. This is on Outlook 2013 and the latest IW 12.1.1.4.  I opened the support ticket but it may take up to 48 hours. Goo luck with that!.  I have not run MS Office repair or try the Outlook profile on the same computer but different Windows account. Nothing else seems to be wrong with the computer. Other applications seem to function just fine and that includes client /server apps. At some point I disable Webroot antivirus but that made no difference. Rebooted IceWarp, firewall. Host name is reachable from the affected computer (public host name). I would appreciate any enlightenment in this matter. Thank you in advance.