Does it matter (I’m asking the question for my own education)?
If you use PowerMatch I think TR is getting pedal-generated power, your bike outside will be pedal-generated power and your FTP is pedal-generated power. I’ve always understood there to be small differences between power meters.
I always assumed that the pedals would read higher. In my case my pedals read almost perfectly with my KICKR Core and about 6% off from my TACX Neo. I’ve not tinkered with any scaling.