Right. So SYSTM is reading power from the KICKR and your Garmin is reading power from the pedals. You shouldn’t expect them to be the same, although if you look at the traces, they should have the same shape.
Also, if you’re comparing Normalized Power, they might not calculate them exactly the same way.
In ERG mode there is no difference between the two: speed, power and cadence. I updated the firmware on the Kickr. The power pedals software is up to date. I see what happens on my 5 rides this week