Spent hours about this topic (EditButton...) This was the only solution that worked in my case. Thank you!

If you can't "see" your app on the device just goto Xcode > Devices & Simulators > Select your connected device > Installed Apps > Selected your App and remove it (-). Try installing again.

Awesome! Thank you so much!

"CloudKit integration requires that all attributes be optional, or have a default value set." If it's not possible anymore to set a default value, the only way for CloudKit would be setting all members to "optional". Really?