DiffInMonths Calculated Field Results in Minutes Label Instead of Months

I have found that in CRM 2015 Update 1 Online, the DiffinMonths field calculation results in a "minutes" value instead of "months". The number is correct; just the label is wrong.

Example:

Field1 = StartDate (date/time format), value set at 1/1/2014
Field2 = EndDate (date/time format), value set at 12/31/2014
Field3 = DurationMonths (date/time format), calculated field

If you set Field3 as a calculated field of DiffInMonths(StartDate,EndDate), the end result will be "12 minutes" instead of the expected "12 months".