I discovered how to temporarily fix the broken Ctrl-A behavior, by doing either one of the following:
Drag and drop an image (png, jpg, gif, etc.) from the Finder into the main text area of a note
OR:
Cut-n-paste in an image from system clipboard via Cmd-Ctrl-Shift-4 (⌘+^+Shift+4).
After the image is inserted into the note, Ctrl-A now works properly within that note only. The inserted image can be deleted immediately after pasting -- recommended unless you want that image to be forever associated with your note in the Snippets & Cards views (this gets to another one of my Evernote gripes).
The image insertion fix does not work with images you copy or cut from another note in Evernote using Ctrl-C or Ctrl-V. The image must be inserted from a screen grab or from a drag-n-drop from the Finder.
This fix is temporary because if you switch to a different note, Ctrl-A reverts to selecting all text, even when you return to the original note where you added the image. So keep a tiny image in your clipboard using ⌘+^+Shift+4 so you can paste & delete it into any given note that you need to edit and want to use Ctrl-A normally.
Control-key workarounds for broken Ctrl-A:
Shift-Ctrl-A, Ctrl-B
Ctrl-P, Ctrl-E, Ctrl-F
If you don't want to spend all day cut/paste/deleting images into all your notes, the above control key combos can be used to move the cursor to the start of the current line you are editing. When the cursor is inside a long paragraph, you'll need to tack on extra Ctrl-N's or Ctrl-P's to navigate to the line of interest.
And yes, the Ctrl-A bug is still present in Evernote version 10.22.3-mac.
I noted this image insertion fix on my support ticket. Perhaps will provide clues as to how to fix the app.