Hey 비우린, it's not the same issue, but proposed fix might possibly work: https://help.magma.com/en/articles/6735730-my-screen-is-glitching-when-drawing-in-magma

If it doesn't help, can you please send us a browser performance report to support@magma.com? https://help.magma.com/en/articles/6684352-saving-browser-performance-report