Same issue here, tried reinstalling the app and playing around with various settings. Now i don't get any notifications although both email and push notifications are checked (Account -> Overview -> Notifications). WebApp says 'Push Notifications - No' for both monitoring devices(browser and app). Made sure android is not blocking any of Pulseways notifications.
Windows 8.1 Pro, Opera browser 56.0.3051.36, Android 9 w/ Oxygen OS 9.0, Pulseway App v5.4.3, Pulseway v6.0.2 build 1001
EDIT: woke up next morning, email notifications are working. Sadly, push notifications still don't work.