So I recently purchased a variety of used android phones for testing an app I'm developing, and they were all fine at first, but one decided to have a problem specifically with wifi. When trying to connect to my home wifi network, it used to get stuck at "obtaining ip address," fail, disconnect, and then attempt the process again in a loop. I got it to successfully connect to my router by assigning it a static ip address, but now, nothing that actually requires a wireless connection works. When opening pages in the browser, the loading bar gets around 1/8 of the way across the screen, and then stops and the browser gives me an error saying I'm not connected to the internet. I tried 2 factory resets and that didn't help at all, so what should I do? The phone says it's connected to the wifi network with full signal, but otherwise it doesn't work. The other 2 phones I have were completely fine and have had no problems.