Stall at 187?

I have a shoulder and it was at 196 (now foiled w a bit of ginger ale for a while now), but I adjusted the probe to a different location and it read 180. It then went up to 189, but decreased to 187 and now is at 185. Am I doing something wrong? Is it normal to stall with the foil on at 190.

Good call. That was probably my problem.