Spyglass is not following correctly the player's head

When using Spyglass in f5 and looking up and down, the spyglass is off centered and is really noticeable when looking up.  Looking down it just looks like I'm just holding normally like I'm not using it.

How to reproduce:

1.Use the Spyglass. (Hold right click.)

2.Go to f5.

3.Look up or down.