If none of what the colleagues mentioned above helped, then definitely try the network test, through the GUI, in the OpenPLi MENU.
Also check the cable if it is a cable connection between the set-top box and your WiFi router.
Finally, you can verify the settings in the WiFi router if the connection with the router is fine (you can verify the connection, for example, by testing with the PING command within your LAN network).
I'm using cabled network.