Sorry to hear that it's unreliable for you guys. It definitely shouldn't be the case. Have you gone through the troubleshooting steps in the app? Feel free to send me a message and I'd be happy to walk through some of the common setup issues. Here's the one that is usually the reason for inconsistent updates:
Verify iCloud Push
1) Open the Settings app on our phone
2) Click "Accounts & Passwords"
3) Click "Fetch New Data"
4) Confirm that:
(a) Push is turned on at the top
(b) In the entry called "iCloud", it says "Push"
(see screenshot)
Best,
Josh