Hello,
Thank you for posting in Q&A forum.
To further troubleshoot this issue, please kindly try below steps:
1.Go to the DNS server and make sure the forwarder configuration is correct.
2.Keep a network trace running in wireshark or network monitor on the DNS server, stop the traffice once this event logged. Search for "DNS" and IP address of forwarder to figure out if there's any DNS resolution failed.
3.Check the network condition on DNS forwarder and make sure it has proper connectivity to the address mentioned in log by ping command.
I hope the information above is helpful.
If you have any questions or concerns, please feel free to let us know.
Best regards,
Jill Zhou
If the Answer is helpful, please click "Accept Answer" and upvote it.