load exclusively the shipping methods that support all the shipping categories of the line items

app/controllers/concerns/checkout_callbacks.rb

@@ -15,7 +15,10 @@ module CheckoutCallbacks
     prepend_before_action :require_distributor_chosen
 
     before_action :load_order, :associate_user, :load_saved_addresses, :load_saved_credit_cards
-    before_action :load_shipping_methods, if: -> { params[:step] == "details" }
+    before_action :load_shipping_methods,
+                  :load_allowed_shipping_methods, if: -> {
+                                                        params[:step] == "details"
+                                                      }
 
     before_action :ensure_order_not_completed
     before_action :ensure_checkout_allowed
@@ -47,7 +50,25 @@ module CheckoutCallbacks
   end
 
   def load_shipping_methods
-    @shipping_methods = available_shipping_methods.sort { |a, b| a.name.casecmp(b.name) }
+    @shipping_methods = sorted_available_shipping_methods
+  end
+
+  def load_allowed_shipping_methods
+    @allowed_shipping_methods = sorted_available_shipping_methods.filter(
+      &method(:supports_all_products_shipping_categories?)
+    )
+  end
+
+  def sorted_available_shipping_methods
+    available_shipping_methods.sort { |a, b| a.name.casecmp(b.name) }
+  end
+
+  def supports_all_products_shipping_categories?(shipping_method)
+    (products_shipping_categories - shipping_method.shipping_categories.pluck(:id)).empty?
+  end
+
+  def products_shipping_categories
+    @products_shipping_categories ||= @order.products.pluck(:shipping_category_id).uniq
   end
 
   def redirect_to_shop?

app/controllers/split_checkout_controller.rb

@@ -24,7 +24,7 @@ class SplitCheckoutController < ::BaseController
     check_step if params[:step]
     recalculate_tax if params[:step] == "summary"
 
-    flash_error_when_no_shipping_method_available if available_shipping_methods.none?
+    flash_error_when_no_shipping_method_available if load_allowed_shipping_methods.none?
   end
 
   def update

app/views/split_checkout/_details.html.haml

@@ -77,7 +77,7 @@
     - ship_method_description = nil
 
     - selected_shipping_method ||= @shipping_methods[0].id if @shipping_methods.length == 1
-    - @shipping_methods.each do |shipping_method|
+    - @allowed_shipping_methods.each do |shipping_method|
       - ship_method_is_selected = shipping_method.id == selected_shipping_method.to_i
       %div.checkout-input.checkout-input-radio
         = fields_for shipping_method do |shipping_method_form|