Poached Chicken to 150, came out very dry and chewy.

I’m following a recipe for chicken salad that called for poaching chicken breast. I got my water to 180 and let the breasts gently come up to ~150 over the course of 20 minutes or so. Using an accurate thermopen instant thermometer. I cut into the chicken and it came out dry and very chewy. What could have caused this? I don’t understand how to make a juicy breast, it seems nothing works. submitted by /u/wilt-oledo