Passive losses are taken against passive income, and only passive income. Once those losses have reduced your taxable passive income to zero, that's it. Remaining losses are carried forward to the next year. As you're aware, it's not at all uncommon for passive losses on rental property to continue to grow and accumulate year to year.
I would fully expect that on the 2018 return you complete next year, line 26 will be even larger. (I would "know" there was a mistake somewhere if it was not the same or larger.)
