You can write your topic however you want, but you need to answer these questions:
- What do you want to achieve? Keep it simple and clear!
I want to messure how much the mouse has moved while keeping the cursor locked in the center of the screen
- What is the issue? Include screenshots / videos if possible!
Mouse.X/Y dosen’t change while moving the cursor if it is locked in the center of the screen
- What solutions have you tried so far? Did you look for solutions on the Developer Hub?
I’ve tried looking for solutions on the hub but I couldn’t find anyone with the same problem 
After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!
What I want to achive: I want the camera to slowly follow the head(like lerping the camera cframe towards the head) while sitting in a first person view. This means that I want the cursor to be locked in the center of the screen and I want to be able to control the camera with the mouse like normaly. The problem is that as far as I know, to control the camera it needs to be CameraType.Scriptable, and when I change the CameraType to scriptable, the camera no longer automatically follows the cursor when I move it(Like it does when I CameraMode = LockFirstPerson).
If anyone knows how to do this or if there is any other way to do it please feel free to comment 
(If you need more information, don’t be afraid to ask away)