I am having the weirdest problem with my MES 40

This is a new problem, as i have smoked in it a few times before with no issue, but never a smoke this long.

last night at 9 pm I put in 2 butts at 225 degrees,  at 12 i bumped it up to 240 the IT was 146  (as far as smoker temps go, both my smoker and redi chek read the same)

I came out at 9am to check the internal temp and it was at 174 and the smoker was sitting at 210, which is what my redi chek read

how ever both the ready check and my smokers built in meat probe both read IT of 174.

Normally my smoker runs hotter then what the display reads.  ( if the display reads 225 it is really around 240, and when cranked up to 275 it can reach 320 in some spots)

Any Idea what could cause this reversal in how my smoker runs?

right now it is 9:50  and i have had it cranked to 275 for a half hour and it has been holding steady at 246

 

OH and i forgot to say that when i raised the temp at midnight the smoker did this weird count down thing and then shut off.

it took about 4 tries to get it to start again, and i watched it for another hour or so to make sure there were no problems

 

I would have agreed but I did my temp checks over yesterday before i started smoking unless the 15 to 20 degree lower temps late at night could cause this kind of dip 

and it was not all that horribly cold out maybe down to 35 at the lowest