When searching for a smart trainer under the Power and Controllable Trainer categories over ANT+, you may see multiple options show up: one of these represents an older ANT+ protocol while the other represents the newer ANT+ FE-C protocol. Mixing the protocols, i.e. pairing to the older ANT+ option under Power and the newer FE-C option under Controllable Trainer, can cause issues ranging from a lag between effort and power to a disconnect in how resistance feels on hills.
This is easy to solve by not pairing mismatched trainer names. For example, pairing "Tacx Pwr" under "Power" and "Tacx Neo" under "Controllable Trainer" will cause problems, but pairing "Tacx Neo" under both won't. To avoid this issue, we recommend pairing to the same item in both categories, i.e. Tacx Neo under both Power and Controllable Trainer.
If available, we recommend pairing to the FE-C category for both Power and Controllable Trainer, as this is the newest ANT+ protocol and works best for Zwift.