This issue has been documented by several developers, but I haven't seen any responses from Microsoft. Wanted to bring it up again on this forum to see if anyone has gotten any further on this issue.

The issue is that RemoteApp client is sending WM_LBUTTONUP messages even when the user has not released the mouse button. Below are several other posts regarding the issue. In my testing, the problem only seems to occur when running Windows Remote Desktop Connections from Windows 7 and 8. Windows 10 client does not cause the issue. Oddly neither does the Microsoft's own Remote Desktop Client for the Mac!

https://social.technet.microsoft.com/Forums/windowsserver/en-US/6c2e1330-0150-4d28-b66b-f37fff58f00d/server-2008-r2-xp-sp37-64bit-client-remoteapp-dragging-window-problem?forum=winserverTS#7c5d2ba5-baa6-4ef0-91fd-4c3cad4acc65

https://social.technet.microsoft.com/Forums/windowsserver/en-US/e5db7477-b35e-4831-886d-9539da218fa5/wrong-wmlbuttonup-message-on-remoteapp?forum=winserverTS#eb72a692-cac7-4595-b1e2-f4be21dcd746

Hi Ben,

I am trying to involve someone familiar with this topic to further look at this issue. There might be some time delay. Appreciate your patience.

Thank you for your understanding and support.

Best Regards,

Amy

Hi Ben,

Due to the complexity of the issue you have described, I would suggest you contact Microsoft Customer Support and Services where more in depth investigation can be done so that you would get a more satisfying explanation and solution to this issue.

In addition, if the issue has been proved that it is indeed a Windows System flaw, Microsoft would refund the consulting fee.

You may find phone number for your region accordingly from the link below:

Global Customer Service phone numbers

https://support.microsoft.com/en-us/gp/customer-service-phone-numbers/en-au

Best Regards,

Amy