So the initial problem is slow operation of Veeam One Reporter.
If you have a big environment(1K+ VMs) it is useful to change data collection interval
from 5 minutes(default) to 20 minutes. Or/and to configure SSRS Server Settings
If it doesn`t help, could you please contact our support team, so we can investigate this behavior closer, since it is to troubleshoot the problem on Community Forums?