Kickr core erg mode question

Newbie to the zwift community as well as Kickr trainers. I recently got a kickr core and am struggling to understand erg mode. For instance I am doing the build me up program and it will call for 90 rpm at 145w, I will hit that target for that interval fine, then it will call for 65 rpm at 170w. I’ve read and watched vids where people say the trainer will adjust to that watt it you adjust the rpms, but this doesn’t seem like the case. I typically find myself in this situation changing from the small ring to the large to hit these targets. Am I missing something. Thanks

Hi have you set the trainer as controllable?

Hey @Billy_Hendrickson, I have a core too and it works great in ERG mode for workouts on Zwift. How are you pairing the trainer (ANT+ FE-C or Bluetooth)? Also, what other devices do you use, what computer or apple tv, phones, HRM, garmin head units, sensors, etc…

Yes I have it set as ant controller

Ant+ and I have my garmin fenix 5 as HR, I had the garmin cadence set but changed that to the wahoo.

are you using the FE-C connection in the pairing screen, power and controllable?

Yeah fec in both