Repro case with a master build: https://codesandbox.io/s/stoic-mcnulty-dhygf?file=/src/App.js:668-703

Expected: we see content after a second.
Actual: fallback never resolves.

This happens in a sequence of:

1. Normal update
   - which suspends
2. Idle update
   - which also suspends
3. An unrelated normal update immediately followed by a ping (so they're batched)
   - here, we decide to stay on fallback, but should've shown the content

If you remove `_setVersion(v => v + 1);` on line 44 then the issue goes away.
return (
          <>
            <Suspense fallback={<Text text="Loading..." />}>
              <Child />
            </Suspense>
          </>
        );
      }
      let setText;
      function Child() {
        const [text, _setText] = useState('A');
        setText = _setText;
        return <AsyncText text={text} />;
      }
      await resolveText('A');
      await ReactNoop.act(async () => {
        root.render(<Parent />);
      });
      expect(Scheduler).toHaveYielded(['A']);
      expect(root).toMatchRenderedOutput(<span prop="A" />);
      await ReactNoop.act(async () => {
        
        
        
        setText('B');
        await resolveText('C');
        Scheduler.unstable_runWithPriority(
          Scheduler.unstable_IdlePriority,
          () => {