Tacx Flux 2 - lower wattage

hi folks,

I’ve had the flux 2 for 13 months. last week I did a calibration using tacx app after I finish a ride. Today when I ride again, I feel that the wattage is under reported. To put it in context, with the usual effort before calibration, I have no problems achieving 1.2-1.3 watt, this can be achieved with no significant effort. However, today, with pretty much the same effort, the wattage/kg that I can achieve only hovers between 0.8-0.9/watt kg.

I try to re calibrate using Tacx app but it wont show calibration finish once I’ve done spin down. Try calibrate in Zwift but it shows time out. My current ftp is 190, I’m sure if I run another test, it will be lower.

Appreciate any help and suggestions is appreciated. TIA