Latency spikes with 2xx responses from requests not reaching my app

Hello,

I’ve recently migrated my Slack bot app to DigitalOcean App Platform and I’m seeing confusing CDN ingress latency spikes that I can’t explain.

Problem

• CDN Ingress Average Latency occasionally spikes to exactly 500ms or 1000ms (not 0.9s or 1.1s - exactly those values) and stay there for around 4-10 mins
• These spikes happen irregularly but consistently
• During spikes, status codes are still 2xx (successful)
• These requests are NOT reaching my application. My app logs show normal <100ms latency during the same time periods

What I’ve tried:

• Disabled edge cache - no impact
• Added health check to /ping endpoint - working fine, less than 1 ms responses
• Checked app logs during spikes - no corresponding slow requests

My confusion:

1. How can requests timeout (exact 1000ms suggests timeout) but still return 2xx status codes?
2. If requests aren’t reaching my app, what layer is timing out?
3. Why does latency sometimes show as 0 despite visible traffic?

App details:

• Go application, single instance
• Health check configured on /ping
• Edge cache disabled
• Custom domain

Here’s a screenshot from low-traffic weekend showing the pattern:

This makes the Insights tab unreliable for monitoring. Any ideas what could cause exactly 1000ms delays in DO’s infrastructure before requests reach the app?

Thanks for any help!