See #17798
? nextFiberChild.sibling
        : null;
      if (nextFallbackChildSet != null) {
        mountFiberRecursively(
          nextFallbackChildSet,
          nextFiber,
          true,
          traceNearestHostComponentUpdate,
        );
        shouldResetChildren = true;
      }
    } else {
       C
       T
      if (nextFiber.child !== prevFiber.child) {
         I
         E
        let nextChild = nextFiber.child;
        let prevChildAtSameIndex = prevFiber.child;
        while (nextChild) {
           W
           t
           S
           W
          if (nextChild.alternate) {
            const prevChild = nextChild.alternate;
            if (
              updateFiberRecursively(
                nextChild,
                prevChild,