Finally in the anim BP, in the class default, there is an option for how you want it to work, basically “from montages only” if your anim will be used in a montage, or “from everything” is for example the anim is used in a blendspace
Try already to check in the preview of the anim itself (my second picture, “process root motion” must be checked). You should see a red line, and the character moving along with the root. It is just for preview purpose, but at least you will see if the root anim is here or not.
You can try also, in the anim itself, to use “zero” or "ref pose " instead of “anim first frame”.