oppo F1S A1601 after Updating 6.0 Network Reset Problem
 

oppo F1S A1601 4Gb 64 gb after Updating from 5.1 to 6.0 Mobile functions Resetting after few seconds Like
Any copy process stopped
Any call running disconnected (Network reset in 1 second only)
all process just stopped for a second

official update available upto 5.1.

Also tried writing security backup of 5.1 but problem is same.