The content of the card will be cleared after submission, this framework behaviour cannot be changed. As a workaround, you can however do the following:
- once the user submits the card, you can extract the input values as usual, but in addition to that, you can post a new card with static values summarising the users inputs, like "Submission received from [user_name] with below details, etc..."
- that way the user will know what they submitted and other users will still be able to submit new data in the same card