Engine revving while in drive

My V8 engine recently started revving when in drive, example = from 1800 RMP to 2200 RPM while at 60 mph. It’s an '04 Jeep Grand Cherkokee with 85k miles. Engine does not rev in park or nuetral. Any ideas why the engine revs when in drive?

When was the last time you changed the transmission fluid and cleaned the filter?

Transmission fluid was changed in April 2006 at 52,465 miles.