Hi @xue28,
Chiming in here as we referred @riccardo644 to the WooCommerce support team. We figured that maybe you have seen this behavior reported before.
The regular payment methods (including the PayPal Payments specific gateways) from linked site should look like this.
Before implementing the workaround with CSS, all WooCommerce gateways were overridden by this card form after a short delay.
So buyers could only use this credit card form which, to our knowledge, is not coming from any payment plugin.
We have seen this exact behavior and card form fields a while back. In that case, an unknown actor modified WooCommerce core plugin files without the knowledge of the store owner. Reinstalling WooCommerce resolved the problem, as the code that inserted these card fields was inside of WooCommerce template files.
There is certainly some unwanted code somewhere on the site that results in these card fields. But from a glance, we haven’t been able to pinpoint it.
So performing a full conflict test to isolate the cause of it to the theme or a different plugin can help. This includes activating the default theme Storefront and disabling all other plugins except for?WooCommerce to see if the behavior persists.
Here’s a guide that explains the steps in more detail: How to test for conflicts
I hope this helps isolate the origin of these card fields.
Kind regards,
Niklas