Story engine bombing out

Three times now, once generating beats and twice generating prose, story engine has just stopped in the middle of a sentence. i.e. it didn't give the "continue generating" prompt, but looked as though it had finished. I was using "most accurate" for the porse on both occasions. The first time it was close to the end (beats 11-12 of 12) after 2800+ words, but now bombed on beats 7-8 (of 14) after just 1300+ words. Not a huge problem, but having to rerun the prose and wasting those words was annoying.