Multiplayer game works in editor but not in a build

Hello, me and my friend are making a multiplayer game for the first time in unity. The game works great when played from the unity editor but if we try to build it, it doesnt work anymore. There seems to be some weird stuff going on with the network since I've logged the network state to a GUI label and the text keeps stacking up. Then the player spawns to the right place but when you try to move its position changes to NaN, 65, NaN.

Here is the error message that it gives when a player tries to join through the build:

transform.position assign attempt for 'Player(Clone)' is not valid. Input position is { NaN, 64.999886, NaN }. UnityEngine.Transform:set_position(Vector3) NetworkCharacter:Update() (at Assets/Scripts/NetworkCharacter.cs:31)

Here is the NetworkCharacter script

Also here is the whole project(its a bit messy since we are still learning git)

Here is the build if you want to test it

Thanks in advance, any help would be greatly appreciated! :)