I reckon it’s one of two things…. Or both.
Firstly the shape of the cavity in your mouth. This is a trial and error thing, but it’s the essence of bending. If you are creating the change of pressure needed to make the bend even without trying then that’s your problem.
The other thing, and I’m only saying this as you say there is a delay in the note starting is perhaps the gapping of the reed.
If the gap of the reed (the gap between the reed and the reed plate) is way too small it will pause and take a heavy attack to play, or not play at all.
A close gap is useful in responsive playing but it can go too far.
The attack needed to make it play may be forcing a bend too.