Or search: vex, cark, upset, worry, unease, disturb, perturb, unhinge, disorder, distract, uneasiness, anxiousness, discomposure
2 Syllables: SU
biased, brightest, cited, climate, diet, direst, driest, finest, guided, highest, Isaac, lighted, lightest, minded, Pilate, pilot, pirate, private, quiet, riot, sided, sighted, slightest, violets, widest, wisest, Wyatt
3 Syllables: USU
delighted, excited, invited, presided, provided, recited, reminded, unbiased, unbiassed, United
4 Syllables: UUSU
carbohydrate, coincided, elegiac

Found 40 words across 3 groupings. Skipped 5 excess words of a similar stem.