1. Open the LabVIEW configuration file (LabVIEW.ini) on the computer.
2. Add the following ini key Editor.Zoom.BlockDiagram.Enabled=False to the configuration file.
3. Save the newly edited configuration file.
Do take note that by inserting this into the LabVIEW configuration file, not only it will disable the zooming feature via keyboard shortcut, but it will also disable the zoom feature via the View menu bar in LabVIEW.
If you want to maintain the zooming feature via the View menu, View>>Zoom In/Zoom Out, but disable the <Ctrl-Mouse Wheel> keyboard shortcut for zooming block diagram, you can add Editor.Zoom.MouseWheelGestureRequireShift=True to the configuration file. By adding this, the new keyboard shortcut for zooming will be changed to <Ctrl-Shift-Mouse Wheel>, while the original keyboard shortcut <Ctrl-Mouse Wheel> feature will be changed to changing sub diagrams for case structures, event structures etc.