Never heard of one acting like that. You don't put any weird/crap gas in it, right? Just normal fuel? There are many electrical things that could cause such problems but bad fuel with water in it could do something similar, and once cars cough their way through some water in the gas they generally keep going and don't set any codes.
When my body control module was being flunky they almost missed it because pulling codes the "normal way" did not yield anything, the tech showed me on his laptop that he had to access the modules from a different interface and then all of a sudden he found bunches of codes but they were apparently not able to flow through all the modules in the canbus properly, and could not be read through the OBDII port as a result. I'm sorry I don't have more specific details on that but maybe it would give the tech at your dealer some inspiration, if there is another way/place they can try to read codes from. At least a couple of us have had to have faulty BCMs replaced and they are apparently highly central to everything electrical in this car.
I always go to my dealer armed with some unlisted youtube video footage of the issue. It was hard to replicate the issues I was having on-demand but I caught them on camera several times and put all the clips into a video with the details and that allowed us to skip over a bunch of BS of having to prove that something was being flaky. In your case, the only way to capture something like that which happens while driving might be to purchase a dash cam and set it up where it can hopefully record the gauges/cluster, I would think the tach needle would flutter and/or some dash light flash momentarily when it happens and if so that would be good to capture. If you can get it to include the driver's legs/feet somehow to show the lurching is not from hitting the brakes that would help, I'm thinking maybe even turn the dash cam sideways so you can get a portrait view of the road, the dash, and the driver's footwork, from over their shoulder angle, and then turn the footage 90-degrees with an editor later. Kind of a rigmarole I know but if you are feeling spunky it is something to try and then at least maybe you can show them. A gopro would work good for this kinda thing too, set up a tripod in the back seat area and pop the record button when you start driving, keep doing it until you capture the problem. Side note, do not do anything silly like trying to hold your cell phone and record with it while driving please...
I've never looked into this but perhaps there is some kind of data recorder you can purchase cheap and plug into the OBDII port and record driving data with, and maybe you could catch something that way, but this also assumes you are pretty handy with a computer and googling up how to do that kind of datalogging. If that is beyond you perhaps there is some performance tuning shop you could hire, good ones use datalogging to tune high performance turbo vehicles and such but they could maybe help you out with capturing data surrounding the issue if it happens often enough. I had a cheap old scan tool which had some kind of freeze-frame menu option that was supposed to help capture data like that but I never had a need to dig into it.
I'm not being much help here other than throwing ideas out. It will be difficult to catch something like that on camera but you might have to try. Asking the techs if they can try reading codes via another method may be worth a shot in the dark, maybe they already did but still. When they discovered the hidden codes in mine they were very perplexed that they could not be read normally and they kept my Compass for 12 days pulling and sending diagnostic data to Jeep engineers to work out that the BCM was the issue. It has been about 6 months since then and everything has been good ever since (knock on wood!)