If things are scaling unexpectedly then they must be attached to and controlled by the Head group somehow. However, if your hands are inside your +Arm groups, that definitely shouldn't happen, since they're independent.
Could you please File > Export > Puppet and share it as a link (Creative Cloud, Google Drive, Dropbox, etc.) here or in a DM so we could take a closer look?
Hello mr samurai sorry it took so long I got caught in another projet
Here is the puppet :
The problem really arrived after i added the +frontal and so on to make walk cycles. Before that it was working.
Sorry I just updated my puppet because I forgot to put back the feets before exporting
Ok guys I found out part of my answer. My character has floating limbs like rayman. And apparently you have to have a connection from your body to your limb in order for character animator to work. So i created a layer behind my character connecting everything and I hide it. Now it seems to have made the trick.
I just wanted to put that here in case someone had the same problem.