Uplinker. A bit like you, I flew the 787 for a short while. Most of the time it was fine but I did see a few times drops of 20kts during capture.
It felt like the system was overly compensating for the impending level off with huge movements of the levers. As a pure guess, maybe Boeing have a simple power reduction logic that only looks at altitude to go vs current ROC, whereas they should be factoring in some combination of CG, winds and temperature delta.