Hello,
Thank you for posting in Q&A forum.
This error can indicate a connection or a configuration issue.
Since this issue only occurs on ipad instead of other clients, we can try below steps to troubleshoot the issue:
1.Check if the RDP client is up to date on ipad, uninstall and install it again if necessary.
2.Check if the network connection between ipad and RDP destination server is ok by ping command.
3.Check if there's any firewall or antivirus that block the network connection.
4.If this is the first time you face issue on ipad, please check ipad settings > Privacy > if local network has permission enabled for the Microsoft RDP client.
To help other customers who may be facing the same issue, please don't forget to vote if the reply is helpful.
Best Regards
Zunhui