Same, they work fine and are immediate. The only exception has been Signal. Must be that I'm using sandboxed Google Play Services?

I use sandboxed Google Play Services, Signal has been fine... I cannot say it's always immediate (I'm not always on my phone :-) ), but I have never been frustrated for "missing" a notification. Like when I check my phone, the Signal messages are there, they don't appear 3 days later.