I chatted with Netflix, they are unaware of the problem and said I should contact Samsung. I chatted with Samsung and they are also unaware of the problem and suggested that I write an email to firstname.lastname@example.org. I did.
I just received an answer from customer support. The solution appears, at first glance, to have worked.
"Please ensure that the Netflix application is not regulated by the battery saving algorythm. Please go to "settigs - Battery and device care - Battery - BAckground usage limits - Never slpeeping apps" and add Netflix to this sction with pushing "+" and choosing Netflix and finish it with pushing "add"."
i have the same issue on my a225g. netflix lags when connected to wifi even after closing everything or restarting. there are no lags on netflix when i tried on iphone and Mi phones