There is plenty of blame to go around here. Hubitat can only fix what it can control. I do think the app needs some improvement, but it isn't the cause of everything not working correctly either.
Geofencing part of the app seems to work fine for me, but my Android phone is another story. Once it goes to sleep for a while, the GPS and Wifi turn off to conserve battery. No phone setting I have found fixes that. If I simply wake the phone it magically re-triggers the geofence. The phone also periodically wakes which causes all sorts of fun middle of the night issues due to "arriving" and "leaving" multiple times per hour.
Geofence also gets messed up when I am in places where the phone is shielded, like my work with the thick walls, metal roof, and metalized window film. My old house with its aluminum siding and radiant roof barrier messed with lots of things and their radios.
I fixed the presence issues by using Combined Presence app, which takes two or more devices and makes a determination whether I am home or not. My second presence sensor is the Smartthings tag/fob, which by itself works well enough, but is nearly foolproof when combined with the phone's Wifi and geofence.