Dont know about floyd roses, had a copy once which was fuqing awful, but ESP are top guitars so yours should be excellent.
When you can afford it this is definitely a job for a tech as those things are complex and it seems that it is not pivoting properly - ie it sticks in either a down or up position. Have a look to see if anything is restricting its movemement at the pivot end and ask ESP for their point of view. Its annoying when quality instruments behave like cheap ones. Good luck.