MacBook display doesn't mirror while using AirPlay

I have a MacBook Prop running 10.10 Yosemite and my Apple TV is updated to the newest software.

When I connect to AirPlay only the sound is heard but my screen isn't mirrored. At first I thought the HDMI cable was loose but I can use Apple TV for Netflix/life/etc. I've tried restarting every system and made sure they were both up-to-date. In the About section on my Apple TV the signal strength shows 5 dots. I'm not sure how many dots are possible, but I assume I have a strong connection as I am the only person using the WiFi at the moment. At one point the Apple TV displayed a 4 digit code labeled "Apple TV code" and I had no idea what to do with it. About 30 minutes later while still trying to resolve the problem a prompt with "Enter Apple TV code" popped up on my Macbook and I put the code in. It did nothing. I'm assuming it would've worked if I input the code the moment it popped up on Apple TV, but I guess my Mac didn't get the message until later so it expired?

This isn't the first time I've used Apple TV to mirror my desktop so I'm not sure what the problem is. Also sorry if this is the wrong community to post it in. I tried to click the Apple TV community but it isn't allowed?