To reproduce:
1. Open the attached project
2. Open the scene "jointTest" (it contains a game object with a hinge joint 2D)
3. Play the scene
4. Open the scene view
5. Click W and try moving the game object

Explanation:
By dragging the object in the editor you are changing the transform component which then warps the Rigidbody2D from position to position which is something you should never do. It's a rule of all physics systems.

Joints desperately try to constrain this situation but the physics system is designed to constrain forces, not objects warping from position to position.

If you are running the simulation then when you drag, you'll see the position per-frame but the physics doesn't update per-frame so the joint tries to update next physics update so the rigid-body will sometimes render at the position you are dragging it to then the joint will try to meet its constraint.