After updating Veeam Backup for Microsoft Office 365 4c (build 22.214.171.1241) backups start to fail with the “Proxy offline time exceeded”.
At the end of every month, Veeam Backup for Microsoft Office 365 collects licensing information. If your Veeam Backup for Microsoft Office 365 server is installed on a server with a time zone east of GMT (GMT +1, GMT +2, and so on) a duplicate record is mistakenly created. Because of this record, the synchronization between proxies and the controller fails and after 48 hours all remote proxies stop working.
Contact Veeam support to obtain a hotfix if you are experiencing this issue.