Repro: https://codesandbox.io/s/fast-water-4i4jb

Notice the flash. I'd expect `suspended` to be `true` during the high pri render.
: (workInProgress.child: any);
          primaryChildFragment.child = progressedPrimaryChild;
          let progressedChild = progressedPrimaryChild;
          while (progressedChild !== null) {
            progressedChild.return = primaryChildFragment;
            progressedChild = progressedChild.sibling;
          }
        }
         
         
        if (enableProfilerTimer && workInProgress.mode & ProfileMode) {
           
          let treeBaseDuration = 0;
          let hiddenChild = primaryChildFragment.child;
          while (hiddenChild !== null) {
            treeBaseDuration += hiddenChild.treeBaseDuration;
            hiddenChild = hiddenChild.sibling;
          }
          primaryChildFragment.treeBaseDuration = treeBaseDuration;
        }
         
        const fallbackChildFragment = createFiberFromFragment(
          nextFallbackChildren,
          mode,
          renderExpirationTime,
          null,
        );
        fallbackChildFragment.return = workInProgress;
        primaryChildFragment.sibling = fallbackChildFragment;
        fallbackChildFragment.effectTag |= Placement;