i use the charger provided by samsung and you suggested to recalibrate the battery. i did that too. no luck. i will monitor this for couple more weeks and will then do a factory reset and then see if it helps.
the only concern that bothers me is that are samsung service center reliable ? the note 8 is waterproof and everbody knows that the seal which is beneath the back panel is gone for good once the phone is opened to change battery. will samsung again reapply the seal while assembling the phone after battery change ? is your phone still waterproof after battery change ?