GOing by CP and CM, I'd tend to agree with you. I think FF might be confused because your temp is very similar. It may very well change your O date as you move further along in the cycle. But yes, I think you are correct.
What is your FF set to? Hover over Settings, and click on Charting Options - down the very bottom, what is the Default Detector set to? I know I found it less reliable when set to Advanced, and I switched to Fertility Awareness... it seemed to take more notice of things like CP and CM.
this link may explain the differences between the settings better