This same behavior also appears to be happening with a numerical input type question

Also multiple numeric question types. Array question types seem to be fine however as are long free text

I noticed these question types have extra logic when looking at startingValues in em_manager_helper.php - not sure if thats the issue
case 'D': //DATE
if (trim($value)=="")
{
$value = NULL;
}
else
{
// We don't really validate date here, anyone can send anything : forced too
$dateformatdatat=getDateFormatData($LEM->surveyOptions['surveyls_dateformat']);
$datetimeobj = new Date_Time_Converter($value, $dateformatdatat['phpdate']);
$value=$datetimeobj->convert("Y-m-d H:i");
}
break;
case 'N': //NUMERICAL QUESTION TYPE
case 'K': //MULTIPLE NUMERICAL QUESTION
if (trim($value)=="") {
$value = NULL;
}
else {
$value = sanitize_float($value);
}
break;
case '|': //File Upload
$value=NULL; // can't upload a file via GET
break;

So this is actually the bit of logic causing the issue:
if (($SESSION['survey'.$surveyid]['fieldmap'][$column]['type'] == 'N' ||
$SESSION['survey'.$surveyid]['fieldmap'][$column]['type'] == 'K' ||
$SESSION['survey'.$surveyid]['fieldmap'][$column]['type'] == 'D') && $value == null)
{ // For type N,K,D NULL in DB is to be considered as NoAnswer in any case.
// We need to set the _SESSION[field] value to '' in order to evaluate conditions.
// This is especially important for the deletenonvalue feature,
// otherwise we would erase any answer with condition such as EQUALS-NO-ANSWER on such
// question types (NKD)
$SESSION['survey'.$surveyid][$column]='';
}

Is this to be expected? shouldn't this behave like the other questions even with token persistence on? Thanks for the help

well thanks for your work !
you did most of it...
I will resolve this one soon

Thanks! looking forward to seeing the solution

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=19146

thank you again for your help, you did a great job.

no problem, glad to help out. Very specific issue, thanks for the fix

I tested it and it seems to work

Version 2.50+ Build 160525 & Version 2.06LTS Build 160524 released