It sounds like you had some trouble with DNS. Not sure if that was due to your local ISP thing but you could switch to some other public DNS services (e.g., “1.1.1.1”, “8.8.8.8”, etc) to see if that mitigates the issue. And if so, that’s likely your ISP/region-specific issue that we can’t help much, unfortunately.
Otherwise, my best bet is to reach out to Fastly support (support@fastly.com) with the debug output collected on https://www.fastly-debug.com/ and see if they can give you any insights.