Go to "Data"＞ "KONAMI ID/Card Game ID" and check which of the following is displayed on the screen.
①"Link to Konami ID" and "Register new Konami ID"
② "Change Nickname" and "Edit account details".
If① is displayed, the data has not been linked in the first place.
If you see ② you have deleted your KONAMI ID after data linkage.
In this case, please reinstall the app and try again to link with KONAMI ID