You should be able to get unemployment. Many years ago, my wife's hours were cut from her Gas Co job and she was able to get unemployment for her underemployment. She says she told them how many hours each week and unemployment adjusted for that.
I'm sure there is a limitation for how much she is making now as well as how many hours she works at her second job. Of course that was for one job. Maybe the fact that it is a second job is the issue.
I'd say if you need the money, file and see what happens. Can't hurt.