Hello Basil,
Thank you for your message.
This was a known issue that was fixed in the most recent updates. Please make sure that you have both Host and Viewer updated to the latest version
7.1.2.0 and there's no version mismatch which can lead to performance issues or some features not working.
You can upgrade your Remote Utilities installation to the latest version by following
this guide.
If your Host and Viewer are already updated to the latest version, please try enabling the
Use legacy capture mode feature in the
Host Settings -> Other tab and see if this helps to resolve the issue. After enabling the feature, please restart Host in order for the changes to be applied.
Hope that helps.