I used to have insomnia if I was hungry before bed. It was actually worse prior to my starting IF, 16:8, but I did experience it during my first couple weeks. Now I prefer to sleep on an emptier stomach. I finish eating around 6pm and bedtime is 9-10pm.
You might be going too hard, too fast. If extending your eating window a couple hours is out of the question, can you move it later in the day/closer to bedtime? Also, are you getting enough calories? I found that adding more carbs and fat to my dinner (meal 2) has helped me feel satiated at bedtime. Lunch (meal 1) remains low carb/high fat and protein. Meal 1 is 500 calories and Meal 2 is 1000-1200 calories. I do that do I’m fullest in the evenings.
Just keep calibrating. You shouldn’t feel hungry all the time, just sometimes, with IF. I prefer to feel hungry in the morning/afternoon and full in the evenings.