Using Version 2.4.2 (1009); whilst the previous versions also had that sort of bug;
UPM is set to 1000; when zooming into very fine details that contain paths and composites (both are very simple) Glyphs becomes very slow regardless to grid subdivisions… and in most cases it freezes so a relaunch of the App is inevitable !
What version of macOS do you have? And what mac?
MacBook Pro connected to exteranl display resulotion 2560X1440 px