The issue you’re experiencing might be because WooCommerce customers and WordPress users are handled separately. Customers will not automatically become WordPress users unless they register an account during the checkout process or you manually create a user profile for them.
To resolve this, you can encourage your customers to register during checkout by enabling the option “Allow customers to create an account during checkout” in WooCommerce settings.
Alternatively, you can disable the guest checkout mode. This will ensure every customer creates an account to place and access their orders, streamlining the checkout process.