Totally normal and covered by the locked top post in this forum:
Turn off Guided Access if you’re on iOS 12 is the moral of the story.
We do recommend Ethernet for more reliable connectivity of course, but relying on a 5S will be a bigger issue than Wi-Fi vs. Ethernet. The best choice as covered elsewhere is to use the same iPad that is (ideally) already used as your primary living room controller as your Simple Hub, and that iPad when put into service should be whatever is the most modern iPad at the time which will give it the best longevity over the years. Whereas choosing a 5S for instance is guaranteed to make you re-do everything soon as it will be the next device to go.