Toyota Corolla Se Saloon 2003 A/T Problem

Dear Brothers, Salam to all. I wish to ask you all a problem that relates to my sisters (family) car which is a 2003 Model Toyota Corolla SE Saloon that has an automatic transmission. It has been driven nicely and has covered over 100000Km (mashallah). Recently after being taken care of properly and with timely maintenance and all it has developed a weird problem. The cars transmission now shifts gears but along with the gear change and rpm drop which is quite normal, it jerks the car slightly which kind of feels awkward. The jerk which I am trying to explain was not present earlier and since the last 2 oil changes (transmission oil) has seemed to appear. Although we have always put genuine ATF Type IV fluid as suggested this gear issue has still not been resolved. We have gone to Toyota workshops only to here that this is a normal issue and a problem in this model(Model Fault, all cars develop this at some time or the other in this category and trim). So we went to many mechanics but still got the same response of this jerk being normal and it denoting a optimum and proper gear shift. (I do not agree on this jerk shift being normal). I mean we have used this car for over 7 years and never have I or my sister seen/felt this issue. Even her driver is saying that this jerk is weird. The worst part is that my brother in law also drives his A/T 3.0L Prado 1998 RZ (Diesel) and his A/T Toyota Corolla Altis 2005 (sold this car earlier this year) but says he has never seen/felt this problem in those cars and this developed in this car(SE Saloon) overtime. As the driver mostly drives the car we want this issue resolved asap as it causes my sister along with her husband (my brother in law) a problem as this is their family car and needs to be used daily and hence this is a huge problem. I wish my PakWheel brothers/Sisters (anyone) can help resolve this issue asap.

Car is fully maintained on timely intervals hence assistance is needed to resolve this issue ASAP. I request all Corolla Owners and Ex Corolla Owners to help me out here. No non-genuine parts are installed in the vehicle.

The Problem in a Summary:

Gear changes from 1st to 2nd - Normal RPM drop - Abnormal Slight Jerk that can be felt as the gearshift is not smooth. @ 2 - 2.5K RPM

(Mentioned RPM cause this is where the problem is felt at max)

Same Problem for 2nd to 3rd Gear but jerk is less.

Somehow the 4th (Final Gear) does not have an issue like this and that transition is smooth. But if O/D (Overdrive is off) this gear does not engage hence all gears are jerky. We got the transmission inspected and every mechanic and Toyota workshop said all is ok.

!! Only some lucky times if the car is driven under 2K rpm (1000 to 1500rpm) the gear change is smooth but that is not possible in stop and go traffic (normal usage) !!