diff --git a/app/models/application_model/can_cleanup_param.rb b/app/models/application_model/can_cleanup_param.rb
index c2f3286fd..751399fc8 100644
--- a/app/models/application_model/can_cleanup_param.rb
+++ b/app/models/application_model/can_cleanup_param.rb
@@ -47,31 +47,27 @@ returns
         data.delete('id')
       end
 
+      # get associations by id
+      attribute_associations = {}
+      reflect_on_all_associations.map do |assoc|
+        class_name = assoc.options[:class_name]
+        next if !class_name
+
+        attribute_associations["#{assoc.name}_id"] = assoc
+      end
+
       # only use object attributes
       clean_params = ActiveSupport::HashWithIndifferentAccess.new
       new.attributes.each_key do |attribute|
         next if !data.key?(attribute)
 
-        invalid = false
-
         # check reference records, referenced by _id attributes
-        reflect_on_all_associations.map do |assoc|
-          class_name = assoc.options[:class_name]
-          next if !class_name
+        if attribute_associations[attribute].present? && data[attribute].present? && !attribute_associations[attribute].klass.lookup(id: data[attribute])
+          raise Exceptions::UnprocessableEntity, "Invalid value for param '#{attribute}': #{data[attribute].inspect}" if exceptions
 
-          name = "#{assoc.name}_id"
-          next if !data.key?(name)
-          next if data[name].blank?
-          next if assoc.klass.lookup(id: data[name])
-
-          raise Exceptions::UnprocessableEntity, "Invalid value for param '#{name}': #{data[name].inspect}" if exceptions
-
-          invalid = true
-          break
+          next
         end
 
-        next if invalid
-
         clean_params[attribute] = data[attribute]
       end
 
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
index e1a652edd..1725d4223 100644
--- a/spec/models/ticket_spec.rb
+++ b/spec/models/ticket_spec.rb
@@ -980,6 +980,12 @@ RSpec.describe Ticket, type: :model do
         end
       end
     end
+
+    describe '#param_cleanup' do
+      it 'does only remove parameters which are invalid and not the complete params hash if one element is invalid (#3743)' do
+        expect(described_class.param_cleanup({ state_id: 3, customer_id: 'guess:1234' }, true, false, false)).to eq({ 'state_id' => 3 })
+      end
+    end
   end
 
   describe 'Attributes:' do