Custom domain returns 502 / connection reset, while *.vercel.app works correctly

Help
1

Hello,
I am experiencing an issue with a custom domain connected to my Vercel project.
Project:
integrator-site
Custom domain:

Vercel domain:
integrator-site.vercel.app
Problem:

  • https://integrator-site.vercel.app works correctly.
  • Both https://ruintegrator.ru and https://www.ruintegrator.ru do not work.
  • Browsers show either “ERR_CONNECTION_RESET” or “HTTP 502”.
  • Vercel Dashboard shows “Valid Configuration” for both domains.
  • SSL certificate has been issued successfully.
  • Domain verification completed successfully.
    DNS:
  • A record for ruintegrator.ru points to 216.198.79.1
  • CNAME for www points to the Vercel target provided in the dashboard
    Additional information:
  • Vercel request logs show successful requests from the custom domain.
  • However, from my network (Rostelecom, Moscow, Russia), connections to 216.198.79.1 time out completely.
  • The Vercel support diagnostic script reports:
    Trying 216.198.79.1:443…
    Connection timed out after 3006 milliseconds
    Ping to 216.198.79.1 also times out.
    Traceroute stops after my ISP and never reaches the Vercel IP.
    The site itself works perfectly on:
    https://integrator-site.vercel.app
    Could you please check whether there are any connectivity, routing, or edge network issues affecting access to the new Vercel IP ranges (216.198.79.x / 64.29.17.x), particularly from Russia?
    Thank you.