All clients are able to connect again without issues.

Root cause is still not fully determined, but we suspect it was due to an internal configuration issue in a few Salesforce nodes. We are following up with Salesforce to understand exactly what happened and how to prevent a recurrence

We have noticed failed decision server requests from some non-US locations. We are investigating the cause.

You may encounter a message like this one:
Callout failed - Unable to tunnel through proxy. Proxy returns "HTTP/1.0 404 Not Found"