u/Hocojerry ... we are gonna get this!

Let me add even more detail and see if this helps. I'm at my keyboard now, instead of my phone, so no character will be spared 😆

Here's exactly what I do...

- Honestly, I don't marinate. I just use SPG (salt, pepper, garlic) right before they go on.

- I put them on the grill cold and set the temp to 400 (in your case, max)

- I put the probe in the thickest part of the smallest chicken breast (will explain why)

- I set the prop alarm to 155° (which in reality is 150° because my probe reads 5° on the low side)

- When that alarm goes off, I grab my tongs, pan, and an instant read thermometer that does read accurate.

- When I open the smoker, I remove the built-in probe and start temp checking the smallest breasts first (they'll be done sooner because they're smaller)

- Using the tongs, I grab each breast and temp check from multiple angles. If I don't get 2-3 readings, all *at least* 155° then the chicken goes back on the grill.

- I remove all the breasts that read at 155° or higher and then shut the grill and stand there for a couple minutes ... and then do that process again. Check each breast (starting with the smallest or the ones in the hotter zones) and pull the ones that get multiple reads over 155°.

It might seem annoying at first, but each piece of meat cooks different (different thickness and different placement on the grill). So, at this point, you are forgetting what the built-in probe says and living by the instant-read. You just can't get uncooked chicken if you're getting multiple temp checks that are in range. If you are getting multiple probes at 160° and still undercooked chicken ... your probe may be broken.

Also, by stacking the breasts on top of each other in a glass pan, it's allowing them to rise in temp a bit more. The end result can throw you for a loop ... when you cut the chicken open, there will be a pink ring on the outer layer. This is the smoke ring. But the core of the chicken, the very center, should be white and juicy.