Vector 3 Calibration not finishing

Have you tried forgetting the Vectors and reconnecting?  I have Rally XC200 pedals that I connected to the 1040 directly (not brought over from my 1030) and they have worked fine- calibration works perfectly. 

Yes, I have tried removing and repairing, but this did not change the behavior.

What software build are on the Vector 3 pedals?

Vector 3 pedals have sw 3.8 and 1040 Solar is on 12.15. And, to be clear, they are reporting power that appears correct throughout the ride.

Has anyone else encountered this? 

Used to happen a lot with me on the 1030 for both Stages and Shimano power meters. With the 1040 it’s been so much faster and reliable (for all sensors I’d say that). Probably because they tightened the ANT+ connection standard (to the annoyance of the people with 4iiii power meters).

So it seems your seeing the opposite.  My 1030 fix was that it was generally still syncing or doing something else in the background.  I generally needed to wait and “wake up” the power meter.  Then it would work (most of the time).

My Vector 3 pedals calibrate at the start of each ride and I can only recall a failure once, but it worked when I retried.  However, note that unlike the 1030 it’s less obvious when the calibration ends.  It does say successful right at the top, but you then have to click back.  The 1030 had an ok button.  Also make sure you wake the pedals up by doing a few spins (although it won’t detect them if you haven’t already done that) and place the cranks in a horizontal position - that’s what I always do and I think that’s the guidance.