Can quitting smoking cause insomnia?

Hi! This question is not for me personally but to try and figure out what is happening with my father (75 years old). He has been a heavy smoker (2 packs a day) for more than 60 years. When he had a stroke back in January 2023, I forced him to quit smoking by refusing to buy him cigarettes. He has not had the physical health to get himself to the store to buy any, so he relied on me and now I don't buy him any at all.
Something clicked in my head just now and I'm wondering if it makes sense.

Since his stroke, he developed delirium and has been very confused all this time. He insists that he's still smoking (he's not). He even keeps lighters with him everywhere he goes and he sits outside on the porch lighting up lighter as if he's lighting a cigarette.
The other thing is, he has not been sleeping like he used to. He's awake the entire day and only sleeps a few hours a night as opposed to pre-stroke where he slept for 2-3 hours per nap, 2 or 3 times a day and same at night.

I used to give him nicotine patches for the cravings but lately, he's been refusing them because he's too lazy to take off his sweater to expose his arm or he insists that he can do it himself without my help (he cannot). I have not been giving him those patches for about a month now, just around the time that I've noticed his sleeping patterns have changed.

I'm wondering now, with the above information, does it make sense that he's not sleeping, causing his confusion/delirium to continue? could it be caused by the lack of nicotine patches and the increase in nicotine cravings?

I am not a smoker myself, so I don't know what it feels like to quit or what the cravings can do.

Thanks!!