Thanks for the prompt response. i have a Nokia 6 android Oreo. Anyways i was going through some of the earlier posts and somewhat figured out the problem. Its working fine since then. Like u said it is a battery saving issue though not specifically "battery optimization". There is a android function in BATTERY SETTINGS called "background activity manager" which stops apps from running in background and draining battery. I took eset off this "blacklist" and voila ! Thanks for the help, much appreciated.