Michael As Nicolas already pointed out, you can access Moodle only under one web-address, where ever the client is. This address is the one you've entered in $CFG->wwwroot. If it is a domain name, then the DNS of the client must resolve the domain name to one of the IP address of MoodleBox - of the wireless interface or the Ethernet (wired) interface. And also the routing of the client must provide a path to that IP address.
But in the case of MoodleBox, there is a rather surprising (undocumented) method, since the MoodleBox is itself a router. You have discovered it: set $CFG->wwwroot to the Ethernet LAN side IP, in your case http://192.168.178.xx (FritzBox?) then clients in the LAN 192.168.178.0/24 have no problem. But also the devices in the MoodleBox's hotspot, 10.0.0.0/24, also find it, because the default route of those devices is the MoodleBox.
You won't break anything experimenting with that. Only thing your need to run the https://docs.moodle.org/39/en/Search_and_replace_tool every time you change the wwwroot of a Moodle instance.