can't undertand what is wrong weight paint fingers

hi, please someone can say me what’s wrong? it’s a file that i didn’t open for two weeks, it worked well last time but now i have a problem with fingers. i added bones last time and i checked all the bones but no one except the right bones influence the fingers. why they deformate? how can i fast understand where is the problem?

EDIT: post another image, the right arm it’s ok, the problem is the left. i can’t understand.

i did a simple armature, then i worked with shape keys for face animations or biceps, i deleted them in the right way but have this. now i controll if i have older file of this