KICKR Strava 'Mileage' vs Tacx Neo for TR Workouts

Hi, I have a 2020 Wahoo Kickr. I am consistently ‘averaging’ 38 kph on my TR workouts when they move over to Strava. On my old Gen 1 Tacx Neo I was doing circa 32 kph. I have exactly the same settings in TR for both trainers, so am I doing anything wrong, or is this down to differences in flywheel size between the two systems? If anyone has a work around for this, like changing wheel diameter, that would be apprecaited.