I’m having the same problem. I have to stagger bedtime in the hope that they don’t keep each other awake. Bedtime is torturous for me. It takes hours of chasing them back into bed, threatening to take away a toy (all this followed by bath, books, etc./ you would think that’s enough). I think they don’t get enough exercise. They sit all day in school, and I guess that doesn’t tire them out enough. I also might be putting them to bed too late and maybe they’re overtired (between 7-8 doesn’t seem too late, though). So, I don’t know. I’m at a loss myself.
I tried the melatonin as per doctor’s suggestion, but didn’t find it helped that much.