max2play switches into Asscesspoint Mode, when no LAN connection of WiFi connection can be found. So please check you LAN cable.
Do the corresponding indicators on the LAN output light up?
Under WiFi/LAN in the max2play interface you can uncheck the „Accesspoint Mode on missing network connection“ and save the settings. This should solve your problem.
I didn’t allow me to save the settings, I had tried that already.
I connected to the Raspi using SSH and rebooted from there, after reboot it was fine again.
Sorry about the inconvenience. For the future, this should easily be fixable by connecting via WiFi (network called „max2play“ and then accessing „max2play“ in the browser to remove the aforementioned tick for automatic AP mode and reboot. If the ethernet cable is plugged in during that reboot, the device will automatically switch connections.