This starts to hit rock bottom to the level of SmartThings support.
The obvious reason to all the reported cloud-to-cloud issues is the failed callback.
Many people reports this sort of issues, not just with Lutron, but recently with Philips Hue, and I had similar experience with LIFX as well.
There should be a way to re-initiate the connection without bombing a whole setup. Where is the user friendly approach in this? Let’s day the user have 10 devices from the integration and built a decent amount of automations/scenes (5-10) and now you are asking to rebuild everything from scratch.
Why are you not reseting your phone for example, to understand how does it feel like setting up home automation from scratch again?
Here lies @JDRoberts’ rule about maintenance free operation. If a Home Automation system starts to be a burden to always pet it and reconfigure it, then that’s were people start to drop it.