Went to have an inspection yesterday and was told my 97s rear brakes need to be replaced to pass. Toyota noted at my last oil change (2 weeks ago) the rear brakes needed replacing, but I assumed they were not that bad since no one discussed changing them that day. New pads and rotors were put on rear in 2020...less than 20K miles ago. I'm not heavy on the brakes and no additional weight (stock)...is this normal? I'm worried maybe calipers or something else may be the issue. Front brakes seem fine.