Steps to reproduce:
1. Login
2. Go to MyAccount->Payment Method and add card details ( 6 or more card details)
3. Notice that all the details get added successfully.
4. Observe that Payment Methods is displaying only 5 payment card details even after adding more payment methods
Could you please check how it works with some default WordPress themes like TwentyTwenty Five or WooCommerce Storefront to understand if it is our theme issue or not?