Distribution List not populating To: line

After the recent update, I had to create a new DIstribution list. When I attempt to send an email to the list, a drop down menu of the list is displayed and I can only select one member of the list. Is there a solution to this problem?

Thanks,

As a test, once you have added the Distribution List to a new message, can you click on the + icon and expand the list to see if the To field is populated with all the recipients?