ZJ 5.9 trans slipping

Hi everyone, I am having some problem with my transmission lately. Once in overdrive usually around 50+ I notice the rpms fluctuating only about 100 rpms. This only happens if it goes under load like climbing a slight incline or if i accelerate to a higher speed. I have read post about the torque converter unlocking but that cause about a 300-500 rpm fluctuate. Mine is only 100- 150 tops! Also if i dont come to a complete stop (still rolling about 5mph) once I step on the gas again it will slip and the rpms go to 2k and then it goes in hard. This does not happened all of the time. Only sometimes. The rpm issue happens a lot more often but still not every time. My fluid level is about an 1/4 to half over the cross hatch full mark. It has been like this for a while and I never had any problem. I will take some fluid out though to drop the level down. I did replace last year the input or output sensor(don't remember which one). First gear wouldn't shift until like 2500 rpms plus it threw a code indicating the sensor. This time with the trans problem no codes are thrown. Any ideas what it could be? Thanks for the help!