Losing 1 promo game instantly means losing lp?

I've been noticing recently that occasionally, when I lose my first or second promo game in the series, my LP goes from 100 to 88-79. If I lose the series, it counts as yet another loss, and deducts my lp even more. Is this supposed to happen? Because it wasn't like this last season, and I'm starting to get confused about this. It definitely makes climbing a lot harder too.