Pages 8.1

The first time that you formally save a Pages v8.1 document with a name other than "Untitled," its autosave feature is enabled. The only means to disable autosave is in System Preferences : General : [√] Ask to keep changes when closing documents.

That setting will require manual saves, and if you quit Pages without saving, a dialog will appear giving you the choice of quitting anyway with loss of all unsaved changes, or to save.

If you have ever had Pages v8.1 crash on you, or had to Force Quit it, then it will misbehave on subsequent launches until you apply the one-time hold the shift key when launching it.

Also, if you are attempting to save a document where you have no privileges to save (e.g. Microsoft One Drive, Google Drive, etc.) then that would also effect autosave.

You are welcome. The shift key solution is only needed just once after each Pages crash, or force quit event.