This article is applicable to plug-in hybrids with model year 2022 Late or later.
The car's high-voltage battery has a cooling system to prevent it from overheating. During charging the cooling system requires energy to keep the battery temperature at a sufficient level.
In warmer climates, or with a lower capacity charger, the car will continue to charge (flashing green light) even when the charging level has reached 100%.
Note
This will not affect the life expectancy of the battery and it is in accordance with normal car behaviour.