Hi Marianna, There is another post here in Community Center in which another host asks the same question. Although neither I, nor any of the hosts that answered that question have changed phones, we are all NOT receiving notifications from the App for the last 24-48 hours or so.
None of know why. I have not reported it and don't know if anyone has yet.
In addition, since this began, (and I think a few of the other commenters said the same thing), the app continually shows that I have one message or alert that needs attention. When I go in, there are none.
If you find anything out, or if I do, please post what you find.