UE4 Networking: Joined player movement is extremely slow / completely broken

Hi everyone,
So i’m developing a multiplayer FPS game and have only just added multiplayer. However, after hosting the server, the player who joined (not the host) moves painfully slowly, and is unable to use the grappling hook mechanic I implemented. However, everything else, including jumping and projectile firing is completely fine. The animations are working fine (there aren’t any in my actual game) and so are the textures and models.
Here is a video demonstration (sorry for the poor quality):

Here is a picture of my MP Game Instance blueprint:

Here is a picture of my server settings:

I have scoured the forums for a fix and have not found anything.
Is this a common bug? Have I done something wrong? Is this just for me?
Can someone please help me to get the movement to normal in multiplayer with this as my game cannot continue without it.

Got a similar problem and also would like to know what the reason could be.