The Gift Vouchers or Gift Certificates are set up as a Virtual Products with the Model starting with GIFT and there is NO shipping on a Virtual Product so ALL shipping modules disappear ...

Settings are:
Product is Virtual: Yes, Skip Shipping Address
Always Free Shipping: No, Normal Shipping Rules
A Gift Voucher/Certificate will skip the checkout_shipping page when setup correctly ...

When a Product is added to the cart containing a Gift Voucher/Certificate you will then see the checkout_shipping and should see your Table Rate ...