I have been using HomeKit on an iPhone 8 and 6s(both iOS 11.2.5) to control six Philips Hue bulbs through my 4th-gen Apple TV for the last few months with no issues.
Yesterday my Amazon Echo randomly stopped being able to control them so I reset the wifi settings(on the echo) and that solved the issue. At the same time my HomeKit also stopped working. All lights now give "no response" warnings.
I can still use the Philips Hue app on my iPhone to control the lights as well as through Alexa.
I am wondering why this may have happened and how to solve the issue.
I have tried restarting my Apple TV, but to no avail. I’m not sure what else to do or how to even go about resetting HomeKit. I can also still use the Apple TV as per normal so it is connected to the WiFi.