Search Console Live Test gives a vague 'General HTTP Error', Rich Results Test says the 'page is unavailable', Ad Words says 'Destination not working'. Bing indexes your site with no problems, and every device you and your friends own works fine, every uptime tester on the planet says you're good. Cloudflare shows no firewall events and logs are a 'contact us for pricing' Enterprise-only feature.
So what do you do - if Google thinks your serverless site doesn't exist, and you can't debug it because it's all magic? You can't do anything. Back to conventional hosting you go.