Date Conversion library no longer cleaning multiple formats

The following code only cleans the first date format:

dateFullYr := '06/04/2018';
date2DgtYr := '06/04/18';

fmtsin := [
'%m/%d/%Y',
'%m/%d/%y'
];
fmtout:='%Y%m%d';

OUTPUT(dateFullYr,NAMED('dateFullYr'));
OUTPUT(date2DgtYr,NAMED('date2DgtYr'));
OUTPUT(Std.date.ConvertDateFormatMultiple(dateFullYr,fmtsin,fmtout),NAMED('CleanedDateFullYr'));
OUTPUT(Std.date.ConvertDateFormatMultiple(date2DgtYr,fmtsin,fmtout),NAMED('CleanedDate2DgtYr'));

WU on Prod: W20180605-100640-2

'06/04/18' returns as blank.

This worked using 6.2.24: W20180528-165002 (Prod)

Reversing the order of the fmtsin will incorrectly clean '06/04/2018': W20180605-100954 (Prod)