Additional, when an other power supply (and CABLE) makes no difference, check the memory usage of all your apps in insights.
(I think you have to enable …More > Settings > Experiments > Power User first).
All apps which are using more and more, and growing over 50 to 80 MB’s (in time), seem to interfere with Homey’s wifi integration.
The Hue app is known for this behaviour for instance.
Homey pauses apps which go over 80MB’s automatically, but for a stable wifi connection it is quite too late.
It can be resolved by using the Device Capabilities app.
You can monitor memory usage of apps, and let them restart when the memory use is too high (say 60MB).
