When the customer tries to perform an undo action with Edit>Undo on macOS or right click > Undo on Windows in a confluence page it undo the previous action instead of the one you trying to undo.
1. Insert a word;
2. Delete a different word;
3. Change the formatting on a third word to make it bold;
4. Undo using one of the following methods right click > Undo or Edit > Undo.
Roll back to the last action.
The editor undo the previous action.
This issue occurs on macOs and Windows.
Use command/Ctrl + Z