Macbook Pro restarts when lid closed power cable plugged in

Hello,

I have searched the forums and found similar problems but none that were actually the same, so I am here to ask for help.

I have noticed after much observation two things:

1. Power cord not plugged in:

-If I don't close the lid, it goes in to screen saver mode and sleep like it should. I move the mouse and it wakes up like it should and I can log in with my password.

-If I close the lid, it goes to sleep as it should. One of two things happen when I wake it up: 1. When I wake it up, it goes to my sign in screen and I log in like it should. 2. When I wake it up, it lets me log in, but then a black screen happens at which I cannot do anything for about 30 seconds. Then, it lets me log in again for a second time but it takes a longer time to load all of my programs that were open, almost as if it half way restarted.

2. Power cord plugged in:

-If I don't close the lid, it goes in to screen saver mode and sleep like it should. I move the mouse and it wakes up like it should and I can log in with my password.

-If I close the lid, it goes to sleep as it should. When I open the lid the screen is black, but the little sleep indicator light on the right front of the computer is still going. I move the mouse around, nothing. I hit space bar, nothing. I tap power button and finally my log in screen pops up. I type in my password and it logs out and goes to a gray screen with a progress bar across it and above that is my profile picture. This happens once or twice and finally I can log in once again. Then, the computer pulls up a lot of "autosaved" files that I had open and my chrome browser will have double the tabs open that were "autorecovered."

Any advice on why this happens when power cord attached and I close my lid?

Thanks,

RJ