https://codesandbox.io/s/upbeat-frost-3tt25

1. Press Suspend, see "Loading..."
2. Wait five seconds, you'll see "Happy birthday" at some point 
3. You won't see it again no matter how long you wait

Expected: you'll see it every five seconds.
This can end up rendering this component multiple passes.
 The first pass splits the children fibers into two sets. A head and .
 We first render the head. If anything is in fallback state, we do another
 pass through beginWork to rerender all children (including the ) with
 the force suspend context. If the first render didn't have anything in
 in fallback state. Then we render each row in the  one-by-one.
 That happens in the completeWork phase without going back to beginWork.
function updateSuspenseListComponent(
  current: Fiber | null,
  workInProgress: Fiber,
  renderExpirationTime: ExpirationTime,
) {
  const nextProps = workInProgress.pendingProps;
  const revealOrder: SuspenseListRevealOrder = nextProps.revealOrder;
  const Mode: SuspenseListTailMode = nextProps.;
  const newChildren = nextProps.children;
  validateRevealOrder(revealOrder);
  validateTailOptions(Mode, revealOrder);
  validateSuspenseListChildren(newChildren, revealOrder);
  reconcileChildren(current, workInProgress, newChildren, renderExpirationTime);
  let suspenseContext: SuspenseContext = suspenseStackCursor.current;
  let shouldForceFallback = hasSuspenseContext(
    suspenseContext,
    (ForceSuspenseFallback: SuspenseContext),
  );
  if (shouldForceFallback) {
    suspenseContext = setShallowSuspenseContext(
      suspenseContext,
      ForceSuspenseFallback,
    );