InDesign 2021 v16.2.1: I have been experiencing viewing issues with the latest update. Whenever I open a file the preview is either blank (grey) or doesn't show correctly/looks glitchy. This happens on all documents that were previously fine. The preview glitch appears periodically when I'm working on the document as well as first open so I have to either close the document and reopen or, strangely, turn on/off the rulers? I haven't seen this before – any help appreciated! I have attached an initial open and after I turn on rulers screenshots to demonstrate. Please can you help?