1997 Jeep Grand Cherokee Limited Loosing Rev?

I have a 1997 Jeep Grand Cherokee Limited that has been running well and well maintained. However, on a recent long trip out on the country road, I experienced what maybe transmission issue. I was attempting to overtake another car. As I pushed down on the accelerator, the engine revved up from a cruising 2k rpm towards 3K, but then it suddenly drop as if it failed to engage the next gear. The car is left in a jerky motion as it attempted to rev past 3k rpm. Yet, if I accelerate on an open road without the sudden rev, it seems to click over to the next gear just fine. Although the accelerator pedal does feel alittle heavier than usual. When this jerky rev motion starts, I have to pull over and turn off the enginer and then it will be fine again. This only happens out on the open country road where I'm doing around 110km p/h and revving to overtake. No issue in city driving. Did I flood the engine in my haste or is the transmission playing up? Advanced thanks for thoughts.