Hello, I've done several tests on the ROM 126.96.36.199 and 188.8.131.52 with the same result, after a while (20 min aprox) push notifications do not reach till you unlock the phone and enter tothe application. I have tried: Whatsapp and all the google apps have autostar permission. Whatsapp is locked in memory, with the padlock. On data usage stats Whatsapp have all enable: data, wlan, background data. On restrict data usage enable: data, wlan. On cleaner disable: clean automatically, memory clean up. I have created a new battery profile with clean memory to never and networks on. On installed apps whatsapp have all enable: allow notifications, priority...On manage apps battery disable the options and also try leave enable and uncheck watsapp of the list of apps to restrict I don't know what is wrong but is annoying, there is something that kill the process or the data background after some time. If you lock the phone it recives push notifications during a time...then nothing, you unlock, on recent apps is the whatsapp icon with the padlock, press on the icon, whatsapps open and after a second you receive all the lost mesages.