You want to set up your DNS records correctly and have your app online, but you're receiving H31 Misdirected Request Errors in your app log.
You might see occasional H31 errors in your app log. If you and your app users can successfully access the app in a browser (or however the app is used), this may not be cause for concern. The errors may be caused by clients (typically web-crawlers) with cached DNS entries trying to access a now-invalid endpoint or IP address for your app.
We’ve updated the app log message to include the user agent information to help determine the validity of the client. If you encounter the H31 Error, the app logs will show the following:
error code=H31 desc="Misdirected Request" method=GET path="/" host=[host.com] request_id=[guid] fwd="[IP]" dyno= connect= service= status=421 bytes= protocol=http agent="<agent>"