Scoop/Slide In triggers permanent sustain

Hello, collective.
I am working on a score right now and there are a couple notes to which the vocalists slide up. Once that note passes in playback, instead of any scoop/slide in, I am treated to a permanent sustain while in playback for the remainder of the chart. Anyone else having this issue or know of a fix?

The offending 2 measures start at mm. 19 in the two voice parts at the top of the score.