Second cook

The 5 lb butts could take 7.5 hrs as the meat will plateau at around 170* for 2-3 hrs while the fat renders. 90 minutes per pound is not unusual. Your briskett will take roughly 70 minutes per pound, maybe longer.

They're done when their done, but if you think 3.5 hrs is long, you've got a longer wait. Based on your posting time, you may have already figured this out. We often start pork butt and brisket smokes the night before we want to eat.

Have you read Pork Butt 101 and Brisket 101? Read the forum topics on each meat also. Ton of information.

Misunderstanding
The oven temp was only 170 at 3.5 hours.
It picked up to 205 after 5 hours.
I excpected to be cooking for 12-14 hours on the brisket.

I don't even want to be the one to tell you this, but it should have come to temp faster than 5 hrs. I think you still need to be talking to Cookshack. Actually, are you sure you don't have a problem with that outlet?

Does seem kinda odd that it would work perfectly for the seasoning run and the first smoke. I'd try something smaller again, like the first time, and see how it runs.

The unit is a lemon.
CS is sending me a new one it will be here Monday.
Temp climbed after 4.5 hrs on meat therm to 175
and cooker temp was only showing numbers from 190 all the way to 215. I opened it up at 6 hrs and that oven was HOT, Hotter than HOT.
I'll put it to the side and wait for my new unit.
The outlets all ohm out at 120 and are working as advertised.

Looks like Cookshack is overnighting it or sending it expedited delivery. Sorry to see you go through this, but at least Cookshack is doing the right thing.

Next week, you'll start posting some great experiences. Hopefully.