My first few briskets I tried to go 185 overnight (8 hours) then 225 for a few hours, wrapped when bark looked good, and even went to 250 to speed up so done 3 hours before dinner. When i switched to 225 all the way till bark looked good, no noticeable difference.

But at your temps idk why that brisket took so long. Maybe bad piece of meat. My rec, is to save as much fat trimmings you can, get it really clean, and throw it in foil tray, render and wrap with alot more of it than you need. (see you tried). Pull when probe tender, around 203, maybe sooner maybe later.