Yes, your next code push indeed made them appear.
Actually, that is a 'tied' pair of 8th notes.
The details page on that site also has several other terms which describe them.
BTW, my bad on the code numbers - I had missed that they are expressed in Hex in their table, but both ways on their details pages.
I am seeing the characters now while still testing FireFox today, but they looked the same in IE8 in the recent past.