My car is VVTI 2005 innova A/T

( this only happen in slow moving traffic. pag dere derecho naman ok ang shifting nya.)

pansin ko minsan delay mag shift innova ko to 2nd gear sometimes ok naman kaka bad trip mag drive minsan. di nag aaccelerate saka na maging 2000rpm saka bigla change to 2nd gear then accelerate bigla ...
pero di naman lagi ganito paminsan lang. is this normal to all AT cars?

last aug lang ako nag pa change ng Differential fluid and ATF.

Any comments or suggestions guys? really appreciate kung sino makatulong sa akin.