No resistance on Wahoo Kickr freeriding

Workouts using ERG work fine, from the last update I’ve lost resistance on the Kickr for ZA-2022 and group rides.
Windows 11, BT dongle on the PC which is v close to the trainer - no connectivity issue. Old Kickr 2015, even older rider.
Tried rebooting Win11
Reinstalled Zwift
Turned off all my other mobile devices
Removed BT dongle to another USB port
No avail
Any ideas ?

Fixed by running a spindown calibration on Zwift.