@trtrtrtrtrtr OK, after few hours I did it work. It required scanning inverter qr code (not the wifi dongle), log in, select network - 2.4 GHz IoT. No other option worked.

@JordiCJ I have the same problem with XE75 (received this today) and Sun2000 5ktl. Can not add wifi dongle to network. Before, it worked with every, cheap or expensive wifi router. Please solve this...