Hello,
Protect the cards you have edited so you do not lose their edits. You can see how to do so here: 🔐 Protecting Fields and Tags
To get the deleted cards back, do the following:
Please try resetting your local changes. To do this:
Go to browse in your Anki → at the top click on the ankihub addon tab → press reset all local changes
This will restore everything to what AnkiHub has unless you have specifically protected those fields