Fix: Resolving box now by instance, not by type. Also, fixing bug where missing shipping driver would break checkout

src/Checkout/Services/CheckoutService.php

@@ -29,6 +29,7 @@ use Modules\Core\Payment\Models\PaymentMethod;
 use Modules\Core\Payment\Services\PaymentDriverRegistry;
 use Modules\Core\Payment\Services\PaymentMethodCache;
 use Modules\Core\Shipping\Contracts\SupportsCashCollection;
+use Modules\Core\Shipping\Support\BoxNowShipping;
 use Modules\Core\Shipping\Support\FulfillmentType;
 
 /**
@@ -181,7 +182,7 @@ class CheckoutService
         // switches BACK to Box Now and it resurfaces as if still chosen,
         // possibly for a locker that no longer exists/fits. Cleared here,
         // the one place that knows the method just changed.
-        if ($identifier !== 'box-now') {
+        if (! BoxNowShipping::isOption($identifier)) {
             $address = $cart->shippingAddress;
 
             if ($address && isset($address->meta['box_now_locker'])) {