Getting 502 errors on 50% of requests in Chrome, but works fine in Firefox

I get the same 502 in Chrome and Firefox. Would you happen to have two DNS records for that vpm subdomain? It’s clearly a problem with the subdomain, but not the main domain. What’s different about the hosting for the subdomain? If it’s not conflicting DNS entries, you’ll have to check the server logs to see why there’s a 502 error.