Upgraded to marshmallow three days ago and it's working pretty fast and smooth.screen flashing like a disco light when screen brightness reduced below 15% did not resolve.4G connection is a problem.GSM only.2G only. 3G only/3G/2G/GSM/ Auto connection mode Is ok.but LTE/WCDMA/GSM Auto connection mode is a problem for 4G network.cannot connect to 4G.signal strength becomes very weak. on the top notification bar appears 4G but can't browse the internet.please add (4G only)mode in the next update.thank you.
