When it's not an electronic issue, it's a mechanical one. An example is a faulty connection between the wallbox plug and the socket on the Tesla Model Y. An imperfect or poor connection results in a lack of contact, and therefore charging will not be possible. Before worrying, it's a good idea to test another wallbox. Then, try another wallbox and compare the charging results. If it works, then the problem lies with the first wallbox that prevented the connection. If this fails, the problem could be with the car's socket. Plugs and sockets may be dirty or deformed. Check for deformations or impurities.