Chiming in to add my experience as well since I've done some pretty extensive testing with SAM 2 & The FlyJSim planes.
At the time of writing this, I am running the most current version of SAM + World Jetways, as well as the latest version of both the FlyJSim 727, and FlyJSim 737-200. I've tested across a nice list of both payware & freeware sceneries, as well as X-Plane Gateway/Default scenery with World Jetways enabled, and have come to the same conclusion that, regardless of the type of airport, the SAM jetways are simply not capable of lowering themselves down low enough to recognize where the door is on any FlyJSim plane at this time, both in Manual mode as well as Auto. In all cases, the indicator that comes up on the side of the screen when approaching a SAM equipped gate does not appear, nor does it appear on first load in when loading the plane.
In some specific & very rare cases, it is possible to trick/force the jetway to connect to the 727 specifically by going into the SAM Jetway control menu, then fast clicking the Manual/Auto swap button in the top right on the window. But because the 727 is very CG sensitive, this only seems to apply when the CG is on center, or far aft making the nose gear (and thus, the door,) be raised up higher than a loaded, or especially heavy 727. This trick does not work on the 737-200 in my experience.
Although, as a user of SAM since basically the beginning, I remember SAM v1 never having any sort of issue with low to the ground aircraft like these, and the jetways would happily lower themselves to the required height to attach to the door. (Though the wheels on the struts would sink into the ground to accomplish this.) In my opinion, letting the jetway sink into the ground a few inches like it used to would be MUCH preferable over the quite literally 1% success rate they have now.
I don't have much experience with the IXEG 733 + SAM even though I do have that plane installed, I just don't wish to fly it any time soon, and haven't in quite some time, but considering it is the same height as the FlyJSim 732, I wouldn't be surprised if it had the same failure rate.
