Currently, when changing the payment method of an existing order (/account/order/edit-payment), the rule engine is not re-executed.

Instead, Shopware continues to use the payment methods that were available at the time the original order was placed.

This results in the following scenarios not being handled correctly:
- Payment methods become valid for the customer retroactively (e.g., based on tags, customer groups, or rules) → but do not appear in the selection.
- Rules change retroactively (e.g., "Always valid" is added) → no update occurs.
- Changes to customer data, addresses, or order items are not reflected.

This means that customers cannot select an updated payment method, even if they meet the requirements after placing the order.

The payment method cannot currently be changed in the admin panel either.

When changing the payment method for an existing order, the payment methods should be determined dynamically based on current data and rules – not based on historical data.

The customer should therefore always see all currently valid payment methods.