What do you mean by it does not work anymore? Make sure as soon as the steamvr dashboard shows up with the warning that you close the dashboard so that vrchat will load with full body tracking. The steamvr dashboard stops tracker information from being sent to the game, because it uses the trackers for input like mouse control. VRChat will not grab the full body setup after it has loaded. So you would need to restart vrchat if it does not detect the trackers because of the steamvr dashboard being open.
An additional note, if you already have full body up and running in vrchat, you can use the steamvr dashboard to temporarily disable full body when you load an avatar. Loading another avatar without the steamvr dashboard open would then put you back into full body for example, as long as the game already knows about the trackers upon first logging in.