When adding the query parameters sorter/field=fixversions and sorter/order=desc I saw an interesting behavior where the fixversions were not quite sorted.

I have the following versions defined (I know the naming is a little weird):

componentX-1.5
componentX-1.4.3
componentX-1.4.2
componentX-1.4.1
componentX-1.4

When I look up JIRAs adding the query parameters sorter/field=fixversions and sorter/order=desc I saw an interesting behavior where the fixversions were not quite sorted. The order came back according to what I observed was the creation date. So in the Administration view I changed the order to put 1.5 above the 1.4.x versions, and then the sort behaved as expected.

I wouldn't expect it to use the ordering from that admin page, however, I would expect it to just sort lexicographically.