Can you click on the tags?
Then click on AK_Step1_V12, all the cards should be there.
If there are no cards there, please do the following:
Please try resetting your local changes. To do this:
Go to browse in your Anki → at the top click on ankihub addon tab → press reset all local changes
This will restore everything to what AnkiHub has unless you have specifically protected those fields
There are no subdecks in V12, to see why, please see this post: Why are there no subdecks in the AnKing V12 deck?
If the cards are there but they are not showing up on the main screen, see this: Why does my AnKing Step Deck have 0 cards?