You should probably use a network monitor and find out what is really going on than making such speculations.
Well, if you know better, tell, so we don't have to speculate.
Anyways, after some more logging, this is the behavior of my Access:
1.) Access connects to atlasapi.myacurite.com right after boot.
2.) It uses Google DNS once in a blue moon to check if atlasapi.myacurite.com still resolves to:
52.4.125.17
52.203.138.112
35.171.190.170
3.) Apart from the above it does not query any other DNS servers.
4.) it NEVER lookup rtupdate.wunderground.com, therefore it must get IPs from myacurite
5.) rtupdate.wunderground.com [prod-pws-ng-546567-997b58a668d15d562a6bed58ea7c5f9e-0000.us-south.containers.appdomain.cloud] resolves to following IPs:
169.60.133.170
169.47.111.58
52.116.188.166
6.) My Access however gets also other IPs from myacurite.
for example (they're many more):
13.224.51.45 (on port 443)
When it tries to connect to these it gets 403 in response and it freezes
7.)
Acurite has to remove these IPs from their pool of IPs and/or hosts it returns to Access.
8.)
Why it doesn't affect all Access devices? No idea. It may be that some of these IP/host pools are cached and not yet refreshed, since Acurite is using Amazon CloudFront for atlasapi.myacurite.com. Probably depends on region and which cloudfront servers it connects to.
Anyways, I'll try and block IPs which return 403 response and see if that helps. Maybe Access will skip those and try next IP in the pool.
AcuRite support wants me to buy a new Access. this was via FB Messenger...
Cute. They really need to re-examine how they do things.