You can undo, redo, or repeat many actions Microsoft Lists, SharePoint, and Teams. You can undo changes, even after you have saved, and then save again, as long as you are within the undo limits (By default Microsoft saves the last 100 undoable actions).
Note: This feature is rolling out in waves worldwide, so you may not yet have access to the functionality discussed in this article until the roll out is complete.
Undo an action
Using the keyboard, press Ctrl+Z. You can press Ctrl+Z repeatedly if you want to undo multiple steps.
Tip: If you're not able to undo the changes you wish to revert, you may be able to restore a previous version of the file. See Restore a previous version of a file in OneDrive or OneDrive for Business.
Redo or repeat an action
Using the keyboard, press Ctrl+Y or F4.
If F4 doesn't work, you may need to press the F-Lock key or Fn Key, and then F4.
Learn more
Keyboard shortcuts in SharePoint