Not sure whether this is just my PC/browser playing up or whether others are also seeing it?
In a change node set to use JSONata, in the JSONata editor panel, clicking to expand the list of JSONata functions and then trying to scroll (particularly using the mouse to drag the scroll bar but noticeable when scrolling with mouse wheel as well) causes the browser to stop responding for a second or 2, occasionally a little longer.
No errors reported in the dev tools console.
Client is Windows 10 20H2, Chromium Edge (latest), Node-RED v1.2.7. Server is both a Pi3 and a full Debian Buster server.