There are likely two reasons: cinnamon may have slowed down the yeast and the starter might not have been active enough.Any reason's why your sourdough did not rise?
I have constant troubles with my pumpernickel. I can literally make one HUGE batch, bust it into two loaves and will rise, and the other will be a pumperBRICKle. It's hit or miss, as you said, it happens but it'd be nice to know WHY at least.
Aaron
I refreshed the starter and added a tablespoon of vinegar to it.
I will also put the dough into the proofer box at 80 instead of out on the counter. The AC was on last night and it might have been too cold in the room.
Sourdough starter does this sometimes though! Wild yeast is un predictable.