Lately my Alexa & Control4 seems to sort of disconnect every day or two (and none of the Control4 devices respond via the Alexa integration).
Initially, I would perform the following actions:
1. Log into customer.control4.com.
2. Click on Voice Control.
3. Under the ALEXA SKILL CONFIGURATION section, uncheck any checked device.
4. Check that same device again to ensure it will be enabled.
5. Click on the Save Changes button.
After a few minutes, my Control4 devices would respond again via the Alexa integration.
Then I realized I could just tell Alexa to "Run discovery" which would get things working much quicker than going through steps 1 through 5 above.