Looks very similar to how my Neo compares to my Vector 3s. In general the Vectors tend to read 6-10w higher
I use the Neo for training and I just have to accept that my outdoor rides will report slightly higher watts.
Looks like the way to go is PowerMatch then, which is what I was doing. I moved away from it eventually as it was difficult hitting short intervals, and response time of the trainer was slow. It’s a lot better using the Neo as power source.
Drivetrain is filthy right now on the bike - I think the chain needed replacing months ago, it is quite stretched. I guess this would mean watts are being lost, and therefore the Neo would read slightly lower?