When I opened the app’s UI, and manually hit some APIs, did not see any 524 error.
But our workers frequently reported ETIMEDOUT errors when connecting to the APIs, ie:
RequestError: connect ETIMEDOUT 10x.2x.4x.16x:443
And at the same time, Freshping reported our other subdomains going up and down intermittently. some are related to the app, some are not. Even our testing Cloudflare’s load balancer subdomain always notified the same ETIMEDOUT error. That’s how I highly suspected this is Cloudflare issue.
Furthermore, I checked with our server cloud provider and there was no issue from their end.