Hello @john-skrhak
Not sure this will help entirely, but here are two articles about the internet requirements.
1. cloud requirements - Cloud requirement: sync server internet access - Lansweeper
2. internet access requirements - Internet access requirements - Lansweeper Community
I think the first link will be more useful as it gives a few tips around what to do when the prechecks fail.
You may want to look into your network/corporate firewall logs when the prechecks run -- see what they say. Maybe they will give some insights into what was restricted/blocked.
Lastly, this is an interesting article that might come in handy as well. This one gives you the components of Lansweeper that require internet access to work properly. This list is not part of the verification checks, but could come in hand when you are performing future scans. Features that require internet access: Lansweeper features that access the internet - Lansweeper
Hope this helps.
Tim N.
Lansweeper Employee