when i ride with my Neo 2 and Vector 3 my Power Output is arround 10-15 Watt higher as with Power measurement of Neo 2 himself, i always ride indoor with my Vector 3 and indoor i have a fine power curve, outdoor it’s different because you ride different, but FTP is the same.
i record every indoor Session with third party software (Zwift, soon with TR) and Edge, the third party software controls my Neo 2 and Edge is only recording, so you can record third party software with Powermeter A and Edge with Powermeter B to see the different.