1998 Plymouth Voyager downshifting problem when comming to

Transmission problem
1998 Plymouth Voyager 3.0 6Cyl Front Wheel Drive Automatic 194000 miles

When comming to a stop with the last down shift you feel like it is not shifting at the right time and kind of hard. I just put new trans fluid in ATF + 4 and a new mopar trans filter and 4.5 qts of fluid. I took it for a drive at first it seemed better than it went back to what it was doing. I was told this trans was rebuilt about a year ago but I dont know if that is true. Thanks for any help. Robert