Samsung Galaxy S6 — WIFI Networks not auto connecting??

Hello, I just purchased a new Galaxy S6 after mine recieved some water damage. This one is an unlocked AT&T version.

I am having some issues with wifi connectivity. I hit the wifi button, select my home network, and enter the password to log into the wifi.

Now, the wifi DOES work, but when I turn off wifi and turn it back on the phone does not remember the network and does not auto-connect to my home network.

This is very irritating as I do not wish to type my password and select the wifi network everytime I wish to connect. Especially when I have wifi connections with other networks such as: Work, Caribou, Mall, Friends houses, etc. To continually remember each one of these network passwords and to select them to connect would be even MORE irritating.