So I think the tracking forb tech is an extension of the technology we’ve seen in the films that can detect life signs on ships or escape pods, except they are synchronized with the biosignature of an individual (I’m guessing with the use of DNA samples). I’ve seen people complain about it making bounty hunting too convenient, but I think you still have to at least be on the same planet as your target to be able to track them hotter-colder style. It’s a big galaxy, so laying low on a backwater world is probably a good idea unless you stir up some trouble or someone spots you in a cantina or something (which is probably how they were found in episode 4).
Sounds like you are trying to sew a jacket to the button.
Nevertheless, it makes no sense.
This a merely “mystery box” thing, that conveniently can move the plot forward.