I have exactly same problem
Was on 11.1.xx, switched to 11.3.9. Did not help.
The service just plain doesn't start. No logs, no event logs (except "A timeout was reached (30000 milliseconds) while waiting for the SQLBackupAndFTP (SQL Server backup) service to connect.)
Great. You pay for product, they give you 1 month of support and after 2 months it simply stops working.
P.S. Windoows Server 2016