The big temp jump occurred after CD17. Also, often O occurs on the day after your last day of fertile CM. I would guess you probably Oed pretty early on CD17, possibly even before temping but not enough time had passed for your P levels and thus temp to jump. Hope that makes sense.
It is super common for temps to rise for a few days right before O. I.e., O doesn't always occur on the day with a particularly low temp.