ptillisch:
Check to see whether the sketch folder or file is read-only. You can do that by following these instructions:
Open the folder containing the sketch in Windows "File Explorer " .
Right click on the folder or file you want to examine. This will open a "context menu".
Select "Properties " from the context menu.
Check to see whether the checkbox next to "Attributes: > ☐ Read-only " is checked.
If it is checked, you should uncheck it to make the folder/file writable.
There is a known bug in Arduino IDE that causes saves to silently fail when the sketch is read-only. This is one possible cause of the problem you experienced.
If you find the sketch is not read-only, please let me know and I'll give you some other instructions you can follow to investigate further.
GREAT! It WAS read only so I unchecked and applied it to folder, subfolders, and files. Did several minor changes and types of SAVE to a few sketches. Looks like you nailed it! SAVED me a lot of grief - pun intended - just in time to go to bed!