Graphic glitch/flickering in the view panel during the writing

Hello, while write in the editor panel the view panel have some flickering glitch.

MacDown 0.7.3 (1008.4)
MacOS X 11.6.1

https://user-images.githubusercontent.com/2394272/146677121-616b7ab5-fccf-4d3e-8c9a-6a3a7c6f5a92.mp4

Start by reproducing the flickering in MacDown 0.7.3 on macOS 11.6.1 while typing in the editor, using the linked recording as the reference. Trace the editor and view-panel behavior to identify the affected area; done means the view panel no longer flickers during writing.

Written by the indexing model from the issue text.