Just wanted to give a warning to anyone using betas. Beta 3 breaks iCloud Reminders syncing. Reminders will not sync between devices or to the iCloud. Many people have already reported the issue to Apple.
DO NOT turn off reminders sync in your iCloud settings or you will be left with nothing. Just a constant spinning loading icon in Reminders app.
The bad news is this also breaks Goodtask as I've tested it. I can confirm nothing will load in Goodtask either and syncing is not working also. So it seems iCloud Reminders is indeed broken in the latest betas.
Just wanted to give a heads-up to everyone... Some people seem to not be affected as I read in the Dev forums but the majority including myself are.