Hi, check the newsletter list where the tracking column should be reported. Is it set to yes or not? The newsletter default is just the default setting when the newsletter is created the first time, but if you set the specific newsletter to no it is kept as no... and if you duplicate a newsletter with no tracking active it keep the no tracking setting (even if it can be changed).
There was a reason to set the tracking to "no" and maybe that choice has been "propagated" duplicating an old newsletter to create the new ones?