Variables not updating with user input

I’m trying to have the speed of my character change with an accelerator button (‘W’ on the keyboard). This worked earlier today, but, according to the debugger, the speed is no longer updating. Here is my blue print for the updating:

modulate speed

Here is the auto-walk that is supposed to be modulated by the updating speed:

And here is the beginplay event, which sets the speed and accelerator:

beginplay

During play, the speed stays constant no matter what I do! Any advice? Thanks!