The links to the legislation types use the current year as the default when linking to the list of legislation. However, if the current year has no legislation, then the year selection drop down lands on the previous year (even though it is rendering the current year).
Because the drop down already has the previous year selected, you cannot change to that year (away from the current year).
If the current year has no legislation, the year selection drop down should not select the wrong year. Instead, there should be a blank option that can be selected.