If you are having an issue with losing your page edits due to Wordpress's live preview feature, the following steps are a simple solution:
1. Right click on the button labeled "Preview" in the post editor.
2. Select "Open Link in New Tab" from the menu that pops up.
Your preview should open up in a separate tab in your web browser. You can then preview the page in that tab, and the editor will still be open for you to make corrections.
After making your corrections, close the preview tab and right click on preview again. Choose "open link in new tab" and you will be able to see the new corrections and still make further adjustments in the editor.