For reference Ticket ID: 766908.
It happens when the control is focused and you press tab in order to focus next control. Available in the 2014 Q1 Release.
when on Month view change year by prev/next button and select same month, year is not saved
It happens with US culture. Available in LIB version 2015.3.1019, it will be also available in the 2015 Q3 SP1.