Somebody else posted this morning they are having the same issue. Zscaler's status dashboard shows everything is working fine, but they did have an incident on Monday that is eerily similar to this, so I'm wondering if same issue has re-appeared (https://trust.zscaler.com/posts/5586).
I'm sure it will be resolved soon, but in the meantime just temporarily disable Advanced Security on your eero network.
Thanks for raising this. eero Secure constantly categorizes new domains and occasionally there are false positives.
This morning the service inadvertently blocked d3ag4hukkh62yn.cloudfront.net which resulted in the blocking of Amazon.com. We are working with our partner to fix this issue and expect to have it removed in the next few hours.
While this won't be the last time we have a false positive, we are working to add an allow / block list feature that will allow you to allow specific websites with advanced security enabled.
I will update this thread once the issue is resolved.