Hey Matt,
Thanks for reaching out! Usually this is some type of networking issues. I would confirm that the SYSTEM account of the machine hosting the publisher has access through any firewalls or proxies being used.
You can also confirm that those vendor domains are not being blocked by referencing our Firewall list here:
https://patchmypc.com/list-of-domains-used-for-downloads-in-patch-my-pc-update-catalog
We can also look into the log files from the Publisher. You can collect them from under the General Tab by clicking the "Collect Logs" button and send them to
[email protected].
I'll review them and will provide any updates via email! :)