"even tried setting time scale to 1 on every tick but even then it does not solve this issue."
Try setting object time scale not global or restore object time scale. Maybe fixes!
Hey thanks for your response but it has nothing to do with the time scale per se. This issue happens only on Android device as something breaks when game refocuses after displaying an ad or any other window. Even if you press home button and come back to the game from task manager this issue still persists. Turns out that this is a bug from Facebook's side. Please refer to the link in Ashley's answer. It hasn't been resolved yet.
Regardless, thanks for your two cents on the problem