Because my tablet was reinstalled in the direct store, and then I downloaded the software again and logged in to my account, but I don’t know why. After logging in again, my previous card is no longer available, and I can’t recover it any way. I hope to receive your reply
I think you accidentally overwrote your AnkiWeb data with your local content. I have restored your AnkiWeb account from a backup made a week ago - when you next sync, please choose “download” to fetch it. You will lose any cards you’ve added since then - if you have some on your local device, I recommend you export the decks to .apkg files first, so you can import them back in.