I assume this is a corporate product correct as all search items show the epo forum so moving it there. Once there read and search that forum for a solution as sorry I am a cnsumer mod and do not use enterprise.
It is a corporate product.
The problem is that the update is successful it is not successful at the time, when the proxy settings are not changed.
Handmade run a task on the VirusScan Console EPO server doesn't lead to positive results.
There are a lot of posts re this with little marked as solved. Been 4 years of this error. See if a corporate mod or user can enlighten you.