1999 Mercury Cougar Hard Shifting

i have a 1999 mercury cougar automatic v6, when i drive the car on the highway for about 10-15 minutes then get off and stop then go to accelerate again it shifts hard like the car gets pulled, this only happends when its hot and when i turn the car off and drive again its perfect, i have a check engine light on and i got it read and the code says p1744-torque converter system perf, if anyone has any info on this let me know

How many miles on that 1999 Cougar? When was the last time the transmission fluid was changed? Manufacturers seem to have decided transmission are disposable. They don’t mention then in the recommended maintenance list. Maybe it might be a good law suit. The automatic transmission fluid and the filter should be replaced every 30-40,000 miles.

i bought the car 2 years ago and have not changed the transmission fluid or filter, the jerking started happening probably over a year ago and always happends when i drive the car fast like highway speeds for like 15 minutes then get back on a city street thats when it starts switching hard, but once its turned off even for like 2 minutes it wont jerk again