Triplets displaying incorrectly

In measure 25 of the attached score, the triplets don't display correctly. There should be three eighth notes at either end and a triplet, equivalent to a quarter note, in the middle. I tried deleting the triplets, creating correct triplets separately, and pasting them in, but the same thing happens. As the score reads now, despite the 3 under the triplet, the singers are likely to try to space the nine written notes out evenly in the bar. Rhythmically, that's wrong. Is there a workaround?