There’s a lot of misinformation here.
Signify, the company behind Philips Hue, suddenly added rate limits without letting their partners (us) know.
Their discovery is not deprecated. Links refering to that are something else that’s deprecated (different url).
The Hue app for Homey makes use of all newest technologies. But when they change something without us knowing, we can’t do much about it.
We updated the Hue app very quickly to avoid the rate limits. Unfortunately, because this automatically restarts the app, and many users already hit the limits in their previous app session, the new app session couldn’t find the hue bridge. Well, shit.
However, the new app is compatible with the new rate limits. Within 24h everything should be back to normal.
Why we’re still using cloud-based discovery? Because we supported the Hue Bridge Gen. 1 much longer than they did. And it doesn’t support local discovery, only cloud.
So now our goodwill bites us. But it’s no excuse. We will migrate to local discovery ASAP.
Thanks for your trust in Homey 
