Whats the potency of your distillate?
Are you taking that into account every time you get a new batch of disty?
If not then that’s probably where your variability is coming from. Also, +/- 5g seems like a lot to me. You should probably try to dial it in to less than 5g honestly.
How big are these treats?
Lets say the disty is 5% of your total formulation and your distillate is 87% THC. You need to adjust your percentage of disty to make it actually 5% total active. Very simple equation 5% / 0.87 = 5.75%
If you’re having inconsistencies across the batch then there is another idea that comes to mind. When you get a jar of disty and the potency is 87% I would hope that they homogenized their distillate before taking a sample. If they didn’t then the results you have could be skewed. If they did and you are the one not homogenizing the distillate before sampling then that could be the issue. THC is a dense molecule and will tend to sink to the bottom of your jar of distillate. Lets say you use 1/4th of the jar at a time. The first fourth is much less potent than the last fourth if your jar has been sitting for a while. Also, you said you are using coconut oil as your carrier oil, I personally would switch to MCT or sunflower oil. A lot easier to homogenize than clumpy coconut oil.
Hopefully that helps! Answering some of the questions posed above will also help get you on the right track. Let me know if you have further questions and I can try and think through this a little more completely with you.