That is consistent with a slightly too long cable looking at the picture. This is based my assumption that the cable attachment triangle is connected to the arm that holds the left brake pad.
Try moving the cable a little a time so that it has more slack at the bars, less slack going behind the seat post. Squeeze and let the lever spring back a couple times to see where it comes to rest and whether or not is an improvement.
Last edited by cb400; 07-26-20 at 01:46 PM.