If the app is not working, as @Brandon stated I would uninstall/reinstall. If Geo-fence (or notifications) are not working, you may also need to remove the virtual device from the hub. I would recommend you uninstall app, remove virtual device from hub, reinstall app, sign-in as registered users, create new virtual device.
Also if you are heavily dependent on presence triggered rules, I'd suggest having at least two methods of detection for redundancy. Consider a key-fab presence sensor, Life360, or one of many others.
Once completed and working again, sit back with a cup of your favorite beverage, and read this brief post on the Early History of Hubitat. Like me, it may give you an appreciation for the youth of this hub, and with that knowledge possibly be more acceptant of it's short term flaws.
In the end if you feel ST is the better choice for you, you can move everything back, or use HubConnect to integrate both hubs and find your own middle ground.
