The Target Time is the time for you to get 100%, the average times are the same as they were (or the same as they normally worked).
But it is a change to the TT and there may be some additional tweaks in the future (comments by erik)
https://www.chess.com/blog/News/chess-com-dev-update-april-28-2017
I am a new player had had just gotten my tactic rating up to 1159. Then all of a sudden I started to losing 11 points for every wrong move. I just looked and it seems that instead of scoring me on the "average time" it is saying I should have solved the problem in 4 seconds a 70% of the time ! The most I should have taken is 21 seconds ! Anyone know what is going on here ? TIA