I stopped receiving notifications from my hub to my phone but was able to start receiving them again by uninstalling and reinstalling the Hubitat app on my phone. Apologies for the simplicity of the solution but I hope to save someone an hour or 2 of frustration.
I have version 2.1.4.07 (447) of the app on my Google Pixel 6 Pro running Android 17. My hub is a C8 Pro.
I feel I had everything set up correctly because the reinstall was sufficient to get everything working. Prior to the reinstall the Hubitat app appeared to be working (other than Notifications) because I could control devices connected to Hub from the phone using the Hubitat app (irrespective of whether I was my local wifi network or remotely on the phone network).
Of course, during the reinstall I had to grant the newly reinstalled app Notification permissions but I'm pretty sure these were already granted prior to the uninstall - maybe the reinstall was what was needed to navigate the maze of Android settings



