[osimj]

#1 (most important): Has a Jeep dealer confirmed ALL applicable software fixes have been applied? The transmission itself (mechanically) is actually a good design and rated at 150% of the Cherokee 3.2l's maximum torque so the metal can handle it. The programing job however was less than stellar. ZF, the transmission manufacturer, developed the transmission but left it to each car manufacturer to develop the shifting software. Honda, Acura, LandRover did an excellent job. You never hear about their ZF 948 transmissions having jerky shifting. Their software engineers were on point. But FCA must have used the second-string programmers for Jeep. They've issued several s/w updates since it was released. Getting all these applied is the absolute first step.

#2. From there, if anything is wrong mechaniclly, it's most likely the valve body might need replacing. While the transmission itself can fail, it's the exception, not the rule.

#3. I have a 2014 TH with 170k miles and just changed my fluid 3 times. Made a HUGE difference. I used to have the same jerky, never-know-what-gear-it-would-choose issues, especially when coming to a rolling stop and then accelerating out. By the 3rd change, it's a completely different transmission. It shifts like a transmission should shift now.

One detailed point about your number 1 answer- the FCA 9 speeds may have been originally designed by ZF ,BUT FCA builds the ones in their vehicles not ZF , and externally they are different with some internal differences too. So along with their poor programming it is an inferior transmission compared to ZF built and better programming by other vehicle manufacturers that are using it.
If I didn’t know or wasn’t told my New Honda had the ZF 9 speed I would never have known they were the same designed transmission as the KL Cherokee. It is far superior the way it functions in the Honda. Smooth , no banging around for the right gear (which FCA made worse by removing the second gear downshift in some early models 14-16 My)
OP has a 15 so they probably have the programming that removed their 2nd gear downshift so it goes from 3-1 and if not coming to complete stop and accelerating to take off again it will delay and bang hard trying to figure what gear it wants. This along with the rest of the terrible programming makes it a jerky ride all the time. New fluid may help some but can’t overcome bad programming controls.

 

[osimj]

Yes, ZF designed the transmission and then they also manufacture (for some auto manufacturers) or, in the case of FCA, they licensed the manufacturing to FCA. This is also why you see slight variations in case style, placement of external items like the TCU, oil cooler etc.

I don’t know anything about ZF’s Quality Control , but one of the shops I worked in dealt with balancing all kinds of parts including transmission parts for Chrysler/Daimler/FCA before the 9 speed was out. The parts we got in were in need of balancing correction due to their workers errors , along with this there were lots of defective parts we received and had to go right into the scrap bin. How many of these defective parts were ending up in vehicles and not being corrected or scrapped instead. I will say a lot based on complaints about Chrysler quality.
This applies to the 9 speed they build

 

[osimj]

Nature of the beast for these rigs. There is some “learning” the computer does so it’ll take time to adjust to your driving. Other than that, like a stick shift you learn how to modulate the pedal such that it won’t jerk and you’ll know what makes it shift bad

That is a BS answer from FCA , my Honda 9 speed from Day 1 has been smooth, Cherokee only got worse especially every time they did programming to address an issue.
Edit: let me refine that statement yes they have adaptive learning ,but the FCA implementation is terrible and should not start out or become a jerky gear searching or banging transmission .

 

[osimj]

Here is a good overview of the 948TE transmission we have in our Cherokees. It is similar to the ZF9, but like it states on Page 3: "Parts cannot be interchanged". On Page 4 it states: "The ZF-built unit is known as the ZF9HP48, while the Chrysler-built unit is known as the 948TE. These transmissions look nearly identical, parts are not necessarily interchangeable." So the same, but different.

https://atracom.blob.core.windows.net/webinars/chrysler/948te_introduction.pdf

Also of note is what transmissions are used in specific vehicles. Chrysler, Dodge, and Jeep use the 958TE. Acura and Honda (same company) use the ZF9HP48. Fiat uses a version called EP2. And Land Rover, well, I can't tell. Since this presentation, more vehicles use the ZF9 or variants.

So it doesn't surprise me that various manufacturers that use the "ZF9" have different experiences. ZF roots for sure, but FCA (now Stellantis) meddling has made it the "un-ZF" IMO.

They do not look nearly identical and this is well known by people who have been on this forum for years. This video has been posted on here many times too. The bell housings are different , the input shafts are different and the case connectors are in different spots, the ZF built one has the cooler mounted directly to it, FCA has line connections to go to remote cooler, and the output shaft of the ZF built has splines on the inside , the FCA built has the splines on the outside of the output shaft.
Just substitute Honda for Land Rover, cause they are identical