Eb Saxophones continuously hold notes they arent supposed to

It seems the text markings above the alto part are not actually chord symbols but another type of marking entirely that have all been edited to resemble a chord symbol. Remove those (and optionally add an actual chord symbol instead, with Ctrl+K) and the playback is as expected.

Yes. See the handbook section on chord symbols (in the text chapter) for more on how to work with them, including how to control their playback. Way simpler than what you've been doing!