by wiki the updates regarding only 6.0 are quite buggy and with flaws
Marshmallow primarily focuses on improving the overall user experience of its predecessor, Lollipop. It introduced a new permissions architecture, new APIs for contextual assistants (first used by a new feature "Now on Tap" to provide context-sensitive search results), a new power management system that reduces background activity when a device is not being physically handled, native support for fingerprint recognition and USB-C connectors, the ability to migrate data and applications to a microSD card, and other internal changes.
Witch in some cases made it worse and with a lot of bugs.
10-11-2018 10:38 AM