This morning my 2008 JK was running fine when I went to pass a slow vehicle, going about 40 mph. The transmission kicked down into a lower gear as expected, but then did not shift back up into a higher gear. The check engine light flashed and it beeped several times. (Light was already on because I need an EGR).
I stopped and everything thing looked ok with the trans fluid. It drove normally, until I tried accelerating hard and the same thing happened. Tried once more and it did it again. Stopped and checked the codes, only the EGR and Evap small leak came up, which I knew about. Don’t have my scanner with me to check deeper.

Anyone know what would cause this?