How to save settings when changing the type of multi-instance tasks from serial to parallel (and vice versa)?

Hello.
For example i have subProcess with multiInstanceLoopCharacteristics


When i`m changing this type to sequential(via pop-up menu)

Then the attributes are removed. How can i save them?
XML examle:

<bpmn:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:camunda="http://camunda.org/schema/1.0/bpmn" id="Definitions_1" targetNamespace="http://bpmn.io/schema/bpmn">
  <bpmn:process id="Process_0xxhxzl">
    <bpmn:subProcess id="Activity_19h7v7w">
      <bpmn:multiInstanceLoopCharacteristics camunda:collection="222222" camunda:elementVariable="3333333">
        <bpmn:loopCardinality xsi:type="bpmn:tFormalExpression">1111111</bpmn:loopCardinality>
        <bpmn:completionCondition xsi:type="bpmn:tFormalExpression">444444444</bpmn:completionCondition>
      </bpmn:multiInstanceLoopCharacteristics>
    </bpmn:subProcess>
  </bpmn:process>
  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_0xxhxzl">
      <bpmndi:BPMNShape id="Activity_01fof9v_di" bpmnElement="Activity_19h7v7w" isExpanded="true">
        <dc:Bounds x="480" y="100" width="210" height="80"/>
      </bpmndi:BPMNShape>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</bpmn:definitions>

Which attributes are removed?