Mobile notifications not working all the time anymore

Hi, I have looked and cannot find someone talking about this exact problem. I have had mobile notifications setup through the MT5 mobile app for Android. It was working fine until a few months ago. Then it suddenly became extremely unreliable. It sometimes works as it should, but other times it does not alert me until I restart my phone. All the alerts are being sent according to the terminal, but they just dont come through to my mobile. I have made sure the app does not sleep and I have disabled any power saving features of my Wifi. It does not matter if I am on Wifi or mobile network, it just seems to hardly every work. After restarting my phone it can work as expected for a few minutes or a few hours, but never seems to last through the day. Does anyone know how to solve this?