Combinatorial machines enter infinite loop

[VanTanev]

Description
A combinatorial machine enters an infinite loop when a root service sends back an event that updates the context.

const machine = createMachine({
  id: "machine",
  context: {
    name: ""
  },
  invoke: {
    id: "name-observer",
    src: () => (sendBack) => {
      // This service is re-initialized on each context change if `states` is not set on the machine.
      // This causes it to send back the SET_NAME event again, and we enter an infinite loop.
      sendBack({ type: "SET_NAME", name: "John" });
    }
  },
  on: {
    SET_NAME: { actions: assign((ctx, { name }) => ({ name })) }
  }

  // if the following is uncommented, the machine does not go into infinite loop:

  // initial: "inactive",
  // states: {
  //   inactive: {}
  // }
});

Expected Result
Combinatorial machines should behave like normal machines. The root invoke service should not be re-initialized on each machine change.

Reproduction
https://codesandbox.io/s/vigilant-butterfly-bi1ei?file=/src/index.js

Additional context
XState 4.19.1

[davidkpiano]

Duplicate of #2147, will be fixed soon in #2149