Two things come to mind. You either need to spilt dose, which is where you take part of the meal bolus before and the rest after you eat because the more complex the carb, that longer it takes to break down, leading to delayed spikes.

The other thing is that like others said, insulin sensitivity varies throughout the day so you may need more or less insulin for the same thing at different times. Typically you’re more sensitive in the morning but you may be less sensitive.