N3048P firmware upgrade path

I have inherited a network full of n3048P switch stacks of various firmware versions and am trying to get them all up to date. I have found on a few with versions 6.1.x.x and 6.2.x.x that after uploading the new file, as per the documentation, the old version still shows as the backup image. I have also tried staging it with uploading version 6.3.3.14 but still have the same result.

Is there a staged step through of releases that I need to do to get these upgraded or am I missing something else?