Multiple applications show a blank canvas where they shouldn't (Android 10)

My phone is a Samsung Galaxy S9+ running android 10 (Kernel version 4.9.186, #1 Thu Mar 31 15:49:59 KST 2022.) Recently I'm finding various applications having display problems where the applications's main text display pane just looks blank though the underlying contents are still there. For instance, in my Joplin App , I see a note's category and title, but the body of the note is missing. This is the case for every note. My synchronization works and I know the content of the note is there because copying it to a different app works fine. It just doesn't show up here. See the screen shot below. Further, there seem to be no complaints in the JoplinApp community regarding this. The back button, menu and drop-down at the top all work fine. The same is true for TheFreeDictionary application, the built-in dictionary app, and I think others. I'm running the latest release versions of each, and my OS indicates that no updates are available. Anyone else seeing this, know why it might be happening, or how to fix it?