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

Notice the flash. I'd expect `suspended` to be `true` during the high pri render.
}
    while (node.sibling === null) {
      if (node.return === null || node.return === workInProgress) {
        return;
      }
      node = node.return;
    }
    node.sibling.return = node.return;
    node = node.sibling;
  }
}
function findLastContentRow(firstChild: null | Fiber): null | Fiber {
   
   
   
   
   
   
   
  let row = firstChild;
  let ContentRow: null | Fiber = null;
  while (row !== null) {
    let currentRow = row.alternate;
     
    if (currentRow !== null && findFirstSuspended(currentRow) === null) {
      ContentRow = row;
    }
    row = row.sibling;
  }
  return ContentRow;