title: Refusing to split GroupedShuffleRangeTracker proposed split position is out of range
body: <p>I am sporadically getting the following errors:</p>
  
  <blockquote>
    <p>W  Refusing to split
     at '\x00\x00\x00\x15\xbc\x19)b\x00\x01': proposed
    split position is out of range
    ['\x00\x00\x00\x15\x00\xff\x00\xff\x00\xff\x00\xff\x00\x01',
    '\x00\x00\x00\x15\xbc\x19)b\x00\x01'). Position of last group
    processed was '\x00\x00\x00\x15\xbc\x19)a\x00\x01'.</p>
  </blockquote>
  
  <p>When it happens, the error is logged every so often and the job never seems to end. Although it seems that it did actually complete the job otherwise.</p>
  
  <p>In the last instance I am using 10 workers and have auto scaling disabled. I am using the Python implementation of Apache Beam.</p>