And now my frustrating results with Android
For my Android tablet I tried to do the same experiments as I did with the iPad. I deleted the Moodle app and restarted the tablet. Then I installed the Moodle app 3.9.5 from the Google Play Store again.
Now I switched to the MoodleBox wifi. The system tool told me that this wifi has no internet connection. The tablet got an ip address, the network mask and the router address. I started the web browser and opened the url moodlebox.home ... no problem. And I could also reach the start page with 10.0.0.1. I logged in and got all the things from the test course. In the MoodleBox dashboard I could see the correct ip addresses of the connected tablets ... the iPad and the Android tablet.
In the next step I started the Moodle app on the Android tablet. I got the url input but the app could not reach the url. I tried moodlebox, moodlebox/, moodlebox.home, moodlebox.home/, http://moodlebox.home, http://moodlebox.home/, 10.0.0.1, 10.0.0.1/. No connection in the Android Moodle app!
After a timeout of about 5 minutes I got the error message:"Cannot connect. We're having trouble connecting to your site. Please check the address is correct. 10.0.0.1/". The ip address is correct but there is no connection in the app.
No, I also got no connection with the ethernet cable connected to the router. It is frustrating! Could it be that the Android Moodle app does not work with Moodle sites which can be opened without https? Or is there a problem with the certificate?
I tested to connect some other Moodle sites with the Android Moodle app and I got no problem. But I could not connect to the MoodleBox.
Is this a hint to the problem? https://tracker.moodle.org/browse/MOBILE-3859