If you are using Bluetooth make sure the trainer is not connected to any device or app since Bluetooth can only make one connection at a time. To connect the trainer using Bluetooth you would need to use the Zwift Mobile Link on your phone to bridge the signal to the Zwift app running on your PC. Make sure within the ZML that in settings>Sensors you have BLE turned on.
You cannot connect the trainer to Zwift on a PC by using Bluetooth directly.
ANT+ is much easier, make sure that the dongle is installed on your PC and make sure you turn on the trainer (button is on the left-side of the trainer and the light will flash once on) and open up the Zwift app and on the pairing screen click search under power source.
Make sure the trainer is broadcast good and is up to date using the Tacx app, but when you want to connect the trainer to Zwift you need to make sure the Tacx app is close since Bluetooth can only connect to one device/app at a time. Also make sure you do a calibration test once in a while to ensure it is working correctly.
BTW, I have a Satori and it works well for Zwift.