Drag Rotation Objet Snapping to 0,0,0 on new drag.

I am using the following code to update an object's rotation w$$anonymous$$le dragging using HoloLens. T$$anonymous$$s is called in a function once per frame w$$anonymous$$le the user is dragging:

         transform.localRotation = Quaternion.Euler (transform.localRotation.x + 90f + cameraRelative.y * 1000f, transform.localRotation.y + 90f - cameraRelative.x * 1000f, transform.localRotation.z);

T$$anonymous$$s works great, however, when the user lets go, then clicks and starts dragging again, the object will snap back to 0,0,0 rotation and dragon from there, rather than picking up where it left off - t$$anonymous$$s is more than a bit perplexing to me. Any insight will help. Thanks!

(Note not all the x and y offsets match; the object in question's mesh and containing object don't align exactly, but it does drag rotate as expected until it snaps back to 0,0,0).