AirPods Pro series 2 case light stays yellow while charging

I have apple AirPods Pro series 2. All work fine and both case and pods are showing 100% charge, but the light on the case is alway yellow when charging - never goes green. Goes green when I disconnect to power as I would expect. Should the case light go green when the case and buds are fully charged when connected to the supply?

[Re-Titled by Moderator]