Hi all. 5 hours into a 20lb brisket. Stall at 155. I'm patient. It's been an hour now ....but she is moving backwards. I am now at 151 and dropping slowly. My temp is VERY consistent @ 225. This is probably my 50th brisket in 18 months and never experienced a negative move. Is this to be expected? Anything special I should look for? Thanks in advance for your thoughts, as always.