High CPU usage

High CPU will occur, when some kind of energy-saving software, e.g. a task manager tries to kill the Telegram process in the background. Telegram process restarts, gets killed, restarts, etc. Solution is to put Telegram on the app's whitelist or remove the third party battery saving app. If not acceptable, disable the Telegram Notifications Service — but notifications will become less reliable, since they are outsourced to Google in that case.