YS 640 Temp Overshoot on Startup

I've had my 640 since November and just installed the thermal blanket. I've noticed since the thermal blanket has been installed my 640 is overshooting the startup temp by 50 - 70 degrees on startup. Also, it takes a considerable amount of time for the temp to decrease closer to my set temp. It doesn't seem to ever hit the set temp, it may get within 10 - 15 degrees high or low.
My software load is U29 and the unit was manufactured in November 2016.
Any feedback would be appreciated.
My software load is U29 and the unit was manufactured in November 2016.
Any feedback would be appreciated.