Problems with wi fi after upgrading to iOS 9.0

After up grading my iPhone 6 Plus to the new iOS 9.0 a couple days ago I noticed that I am unable to connect to some wifi networks. For example, I can't connect to the wifi at work. In fact, iIt looks like everyone at work that installed the upgrade is having the same problem. I tried resetting the network settings but it didn't do anything. Has anyone had the same problem?