-e: see title

-repro:
--open test scene from attached project
--select the object with the animator controller
--open Animation window
--create new clip
--select a bunch of sprites from the cat folder
--drop them onto the dope sheet
--notice clip length
--change sample rate from 60 to 12
--NOTICE the clip is now half empty at the end

-works well in 5.4.1
-workaround: add another keyframe at the end