On the retargetting panel, tick show advanced options or something like that. Then change the bones’ retargetting method to skeleton to the bones affected.
If you have already, check the skeleton again because it really looks like this is the problem, you might’ve been changing the animation instead of the skeleton.
Additionally, check that the pose is similar between both skeletons.
I didn’t manage to get the missing bones from the fingers retarget properly, but it solves the arms issue on your first picture. How did you get the fingers not get funky?