I'll make it simple if fs could be dodge easily with normal coo then what's the point of getting fs
![Kayneshrug :kayneshrug: :kayneshrug:](https://worstgen.alwaysdata.net/images/smilies/symbols/Kanyeshrug.png)
Normal CoO doesn't 'dodge' Future Sight, it just helps one be aware of their immediate surroundings. The classic rule of future events and time travel, is that if you intervene and change the predicted future, then the predicted future changes and is no longer the same as you predicted.
Katakuri foresaw Sanji dodging father preist's bullet, so he intervened before Father Priest even took the shot- intervening in that Future, disrupting it and making it no longer the same as he predicted, in this case Sanji dodging his jellybean. Katakuri was too hasty.
But Sanji himself dodging his jellybean had nothing to do with Future Sight Observation Haki, he either saw it out of the corner of his eye, or it was just his normal Observation Haki sensing a projectile coming into his immediate surroundings. Observation Haki allows one to dodge a incoming attack from behind even when blindfolded (as evidenced and seen in Rayleigh and Luffy's training), so Sanji dodging a jellybean out of the corner of his eye isn't out of the ordinary for a CoO user.