The Network Manager asked you the password for wifi1 and you typed the right password on this network. Then, the network manager found a better signal and put it on the top but it was not connected to wifi2, only to wifi1.
I often have the same problem at home with two different wifi signals. In order to see whether you are connected or not you must click on the Networks icon on the menu.
Of course, I can change from one to the other because I have entered the password before and it is recorded. Otherwise, I could not access to the wifi network. So, the question is the following: Did you provide the passwords of wifi1, wifi2 and wifi3 before you experiment this problem?
At last, when I have selected a wifi connection the Network Manager did not change it because of the signal strength although I want to change from the Network icon.
Hope it help, regards.