Can you send me logs from the folder: C:\ProgramData\Veeam\Backup\ExchangeExplorer\Logs ? My email is email@example.com
184.108.40.2066 is a Veeam Backup & Replication 9.5 build (and it's a different solution from Veeam Backup for Microsoft Office 365). To recover/export Microsoft Exchange items, Veeam Backup & Replication uses the Veeam Explorer tool, and it seems that your issue can be related to this tool. I'll check the logs and get back to you.