307 gears up, stuck

Good day friends, we stuck in traffic for about 3 hours on the way from Istanbul to Ankara, then the gear started not to increase, it decreased when the revs decreased but not when it increased, I turned the car off and on, it was okay, but it happened again, it did not work when I rested it for the third time, I expect your help.

It takes it to protect itself when it gets too hot. The solution is to install a new generation gearbox oil cooler in my vehicle.

I get it, teacher, we'll take it to a master, thank you