In two Lumia 535, with WP 8.1 and another with W10, both connected to an original charger do not charge well. Until it loses all the load it does not start charging, and when it starts to load, the charging is very slow. I tested the charger on other devices, such as Lumia 532 and 640, and is working normally.
On WP 8.1 loading this up faster, almost normal.
What could be the problem?