There are a number of devices that have trouble connecting to a dual band WiFi network that routers like the Time Capsule provides. That being the case, have you assigned a different name to the 2.4 GHz and 5 GHz networks, and "aimed" your Ring and Cocoon devices at the 2.4 GHz signal?
In addition to the comments provided by Tesserax, the actual name of your WiFi network can cause connection problems for some devices, especially if the name of your WiFi network contains special characters like an apostrophe, asterisk, dollar sign, etc.
Good rules of thumb for naming WiFi networks would be.........
Short, no more than 12-16 characters in the name, less is better
No special characters in the name of the WiFi network.....use only normal letters and numbers
No blank spaces in the name of the WiFi network......some devices can pick up a blank space as a - (dash).