I was alerted of an issue with notifications a few weeks ago and had already started working on 11.2.3. During the process, I looked in to see why there were not notifications and I found some settings that were held over from the old push service and some other settings I needed to ensure were set for the new push service. I'm happy to report that it looks like this is fixed in 11.2.3 and I am hoping to have that out very, very soon!