On my 2003 Chevy Impala with 127,000 miles the car jerks like someone has hit you in the rear end, it usually happens from first to second and is becoming more frequent. A recent transmission service had no effect
You’re going to need to take it to your best local, independent (i.e. non-corporate chain) transmission shop. Someone will need to put it on a scanner to check for error codes and watch what the transmission is up to. If you come up with codes and other info you can post them here for comment/advice.
What was done in the recent transmission service? Was the pan dropped and filter changed? Was the transmission ever serviced before this?
Be prepared for bad news.
A recent transmission service had no effect
What was the prior history of transmission service. Was that recent transmission service the first one? I hear a lot of complaints about transmissions that were never serviced until the problems of poorly maintained transmission became apparent. Waiting until you have a problem is too late to prevent it.
Sorry