From what you described on the brisket, I can't tell what might have went wrong. But, if you're not fully experienced with smoking, I wouldn't suggest smoking 2 meats at the same time.
I've been doing ribs for many of years and I've learned for me, 225* is not the right temperature. For me, 275* is the sweet spot. With the St. Louis ribs I get from Costco, I'll either smoke them straight for 4 hours (and they're perfect) or will do 2-1-1 (2 hours smoked, 1 hour wrapped with my mixture and betwn 30 minutes to an hour unwrapped). They always come out perfect...Research some of my pics if you want to see an example. For me, if I ever mop/spray the ribs, I'll do it 1 or 2 times and no more. I don't want soggy food and if you rubbed them good, you won't need a mopping. And, I've noticed that some people go to crazy with mopping/spraying. Think about this, are you mopping off your rub?
Well, brisket is a difficult make to perfect. Just keep at it.