Well, I called Rich at rbasics and we figured out my issue. After putting an accurite directly on the heat tape I found its rock steady so is not a heat tape nor a thermostat issue. Rather its my substrate.

I use Aspen which is acting like a blanket and causing my temps to fluctuate due to heat build-up within the tubs itself. Would also explain why I've had to set my herpstat 4-5 degrees below target temp.

So I'm switching over to paper towels/newspaper for the foreseeable future to fix this issue because when I had my bp on towels I didnt have these problems.

Sigh.... I hate paper towels.