Cubots are unreliable.
I own a Cubot J3 and my wife has owned 2 more expensive models. We bought them because we were told they were good quality and the prices were good for the spec. However all of these phones have failed for different reasons after a very short period of use, 2 of them in less than a year. We were also advised not to try getting them repaired under warranty because they were all software problems. Really not happy.