I’m continuing the discussion from here. I’m not able to receive Signal messages until I open the App. I am very sure this is caused by Google Cloud Messaging, since another messaging app I use (Kontalk) which does not rely on Google, does work. I made sure I installed the latest Signal and OpenGApps versions, but it doesn’t work.
as a sidenote the Signal Devs are now planning on removing the dependecies for GCM.
Hopefully that ends a lot of hassle and will enable (not yet techies) like me to switch to FP Open!