The tools update script is needed if you build Unreal Engine from source (github) but not if you just use the download.
i am adding Code to the AI "TrackerBot" but that is somehow effecting my Character which seems odd to me.
How confident are you that your C++ code is correct, and that you're not using something like global or static variables that let data "bleed" between objects?
How confident are you that your character has the correct controller assigned? (Characters need controllers, especially in networked games -- trying to drive Character/Actor directly is bound to fail because you're going against how the engine wants to work.)
Can you get a simple multiplayer project to work correctly, using blueprint? If so, start looking at what's different between that project and yours.
Here's the YouTube videos I was talking about, I highly recommend them!
There's a little bit of networking update in 4.20 and onwards, here's another series of videos:
Looking through these videos will likely help you get another view into how networking in Unreal is supposed to work in general, which will probably help you build up the skills necessary to debug whatever your current problem is.
Another option is to start at the beginning, set breakpoints where your character is supposed to receive movement commands, and set a breakpoint where the keyboard input generates the movement commands, and then step through it all in the debugger, making sure that the data goes to the right point at each step. At some point in this process, you will find that the command somehow gets ignored, dropped, changed, or countermanded, or maybe just not sent upstream, and that will be your problem.