I tried to make a working walk animation by detecting a variable called WalkTrue. It didn't work for me, maybe its my computer
https://scratch.mit.edu/projects/128686617/

The problem is the way you use forever loops.

As I often do in these posts, let me please encourage you as a new Scratcher to just pretend the forever loop does not exist and don't use them in your project.

What you have is something like this

What's happening here is that you are getting into the inner forever loop and never leaving it, thus the outer forever loop never restarts to reset your variable.

Instead change this to use