Took a trip to Houston this weekend(240miles). Normally I run around 2200 rpm at around 70-75. Halfway there the rpm jumped to around 2900. It is like overdrive stopped working. Stopped to eat for around an hour. Got back on the highway, normal rpm for about 30 min then jumped to 2900 again. I have a 2013 jku automatic with a procal. Have never experienced this before. Any suggestions?