Push for Monal has worked flawlessly for me for about a year now. However I also heard it didn’t work reliably for everyone. This was not something that I was able to replicate. After a lot of help from others we were able to identify the issue as something specifically odd about the interaction between ejabberd servers and the prosody server that powers push for Monal. This issue with the prosody module appears to have been fixed and I have upgraded my push server.
In theory this server side change should fix push for everyone and there is no app upgrade necessary. Please let me know if you are still experiencing push issues.