From ZENworks 2020 onwards, a new, upgraded Remote Management (RM) viewer is introduced. The new Remote Management viewer (mzrViewer.exe) is based on the latest stable version of VNC viewer code, which includes several bug fixed, and provides better performance while remote controlling devices. Hence, you can now choose to use the old or new viewer based on your requirements.
By default, the new viewer uses Tight encoding scheme, which enhances performance while remote controlling devices that are in low or high bandwidth environment and also provides better performance for Windows devices.
From ZENworks 2020 Update 1 onwards, by default, the new remote management viewer will be used. However, if required, you can select the Use the legacy Remote Management viewer option to use the legacy viewer.
For more information about the Toolbar options in the Remote Management Viewer, see Managing Remote Sessions.