I live in Germany and have tried a few mesh wifi systems, due to the thickness of the walls here they have all failed to provide reliable wifi to the furthest rooms in my home. Deco was the first one to remain connected to the main router and give adequate coverage. 
 

We have a dozen or so products connected to our wifi ranging from MacBooks to chromecasts. The issue only occurs on my iPhone. While trying to connect to the wifi, if i simply click on my wifi network in settings it will redirect me to a pop up "captive.apple" and give me an error message "could not connect to this network". I have to click on the additional details in settings and connect from that menu. This would be fine if it stayed connected, however through the night it always disconnects. Coming home doesn't automatically connect either. Each time i have to manually go into my settings, select the additional options in my network and connect that way. It's quite frustrating as the signal is perfect. 
 

I have tried forgetting the network, changing password and network name, checked firmware updates, and re-downloaded the app. I've also scoured the internet only to find similar issues but none mentioning the redirection to the "connect.apple" page.