Redmi Note 4: Problem 15 Minutes Long Switch On

Jun 6, 2018
Dear all,
Since 1 week ago my RedMi Note 4 (RAM 3GB and 64GB memory, MIUI Global MBFMIFA stable, CPU decaMax 2.11 GHz) showed a switched on procedure that last up to 15 minutes, most of the time with a black screen blocked with just the MI logo.
Anyone know the reason and how to sort it out?

This is the last of the problems I had with this smartphone that I bought it 1 years ago.
The battery is drained fast, consumed mainly by "Stendby cell" which sometime reach 60% of battery usage. I changed SIM buying a new one from second 1°class phone company, so I exclude the problem is related to the SIM.