See title, saturation is an instant effect (as seen in the /effect command where the duration parameter is in ticks then, instead of seconds), while all other flowers give a lasting effect.
This instant effect actually sticks around for 5 seconds, rather than 1 tick.
Linked issues
relates to 2
Comments 5
For anybody saying this isn't fixed because the suspicious stew grants the effect for more than one tick, it actually is because the developers intended for the stew to restore a hunger point every tick for 7 ticks instead of 7 seconds. What would be the point of adding a timer if the effect went away within one tick?
Confirmed for 19w09a