Disable Autosave
File>Settings>Appearance & Behavior>System Settings>Autosave> then uncheck bothSave files if the IDE is idle for |15| secondsandSave files when switching to a different application>Apply

After doing the above, you may like to do enable the following 2 options too-
Mark Changed But Unsaved File
File>Settings>Editor>General>Editor Tabs> then checkMark modified (*)>Apply

Save One File with Ctrl+S
File>Settings>Keymap> search with save document > right clickSave Document>Add Keyboard Shortcut> press Ctrl+S>OK>Remove>Apply
