Roberts saw noticeable improvement among Independents and Democrats, though both groups continue to dislike him. Moderates are the only ideological group that has really shifted. Brownback saw his disapproval spike among independents, but everyone else seems to be just drifting. He regained some ground among conservatives (who disapproved of his immigration stance).
I find the Roberts numbers confusing. His name hasn't been in the news much, so there's no reason for people to be changing their minds.