cant see the arduino uno wifi SSID in the list

hi everyone,
i am trying to initially set up arduino wifi to connect with one of the available wifi which i can access (as mentioned in "first cofiguration"). however, after that, i realise for some reasons i cant switch the wifi mode to sta. as a result, i disconnect the board and redo from the first step. the problem is that from this time, i cant see the SSID shown in the available wifi list anymore as its shown before. i was using the public wifi to connect with the arduino uno (i cannot disable wifi access point to reset the board). could anyone here have any ideas to solve this problem? thanks.

Do you have the Uno WiFi or the Uno WiFi Rev2?