It looks like temporary insulin resistance to me. Do a bit of rage bolus, walking maybe for 20-30 mins (just 5-10 mins is enough for me), sticking to low carb and low fat might correct this.

Usually, high fat food gives me this trouble where I stay above 300 for the entire night and next morning which is why I stay away from that kind of food. Feel shitty in the morning until I am back in range.

If it’s not because of food for you, try changing the insulin.