Amortization schedule shows amount applied to interest going up?

[Kevin Dubina]

I have a personal loan for one of my properties (not a mortgage). The amortization schedule shows the amount applied to principle and interest jumping around substantially every month. I would have thought the amount applied to principle should always go up and the amount applied to interest should always go down. Does someone have an idea what may be going on? (I'm trying to include a screenshot for reference)