Animation in Unreal

I am wondering if you make your character actor/ skeletal mesh replace the third person character actor in unreal why does it just keep its T stance?
I tired to use unreal third person amibp blue print but it doesnt seem to take it
Also Tried editing the unreal animation idle and walk and use them in a Animation Blend1 but the clips wouldnt get in the editor any idea? Or should I just stick to mixamo for rigging and animations?

likely the skeleton animations are bad / not compatible with the skeletal mesh you selected.
You would likely need to re-target the animations.

Also, the Message Log or the Output Log will tell you exactly why the character is in a T stance (which should really be an A pose btw, for precision sake).