I understand macOS Sequoia is in beta
from your own link, it was released on Sept 16th … so 8 days ago 
If you search for “macOS sequoia network issues” sans quotes, there are a plethora of reddit and other posts about issues - so I would tend to think this is an OS issue but IANAE - I actually have a mac for testing, but not updated it yet (and it has no VPN or ESET or Little Snitch etc - pretty much factory + updates)
examples