Hello everyone,

I encounter a problem with my MX4 recent weeks.
he sometimes lagger or become slow whatever the app called (calendar, Play store, contacts…).
I was in FlymeOS i v4.5.7 and I switched to firmware 5.1.5 g .
By flashing I made ​​a clear data but the problem still exists.
To test I even tried to downgrade to FlymeOS i v4.2.2.2 (with clear data) without success.
I noticed that when I made ​​a clear data, parameters and applications are erased but the pictures or videos in the DCIM folder are still there. Folders in the root of the SD card are not deleted too.
Is it normal ? Is there a way to completly format the device to get real hard reseted phone without any data ?

Thanks for all