Says connected to wifI, but some apps say that there is no Internet connection

[AC Question]

Okay, so this morning YouTube and GooglePlay said that I wasn't connected to Wifi, when I was. I can tell that it is not the wifi, as my phone can connect to the wifi.

Later in the day, I decided to factory reset my tablet, and the same thing happened, I tried to connect to my Google account, but it said that it wasn't able to connect to wifi, when I was connected to the internet