I can only offer one sturdy thing that’s helped us. Melatonin. Our son, his ENTIRE second year would scream from dusk to dawn. Every single night. And he wouldn’t nap during the day. We tried everything. It was a year of absolute hell and all I could do was go sit in my car at 3 am to scream and ball my eyes out myself. It was so agonizing. As soon as he turned 3, we introduced melatonin and haven’t looked back. He now sleeps through the night, and that is truly the only thing that helped us.
I don't know how to help, but I can provide empathy, because my 3 yo stepson laughs when he gets in trouble as well. It's frustrating when they don't understand what we're telling them, and that they don't follow instructions!