We've had a quite a few issues with updates that report 'Error On Endpoint:Couldn't resolve host name' or 'Error On Endpoint: permission denied' in addition to issues with the monolithic zip file with patch information not downloading.

We escalated a support ticket and they haven't figured out the first two 'transient' issues, but they are aware of the large patch info zip file issue, which is supposed to be fixed in the most recent releases - we haven't moved beyond 9.5.0.25 yet - so hopefully it will get better.

We worked around the zip file issue a bit by changing our scanning days to be Monday and Wednesday and avoiding Tuesday when the file is released.