I have 2 similar models (just not the curved version) and experienced some dropouts early on, including some 1080p content.
If you are unable to simply switch to a wired connection as Bob has wisely suggested, look in greater detail at your home wifi network, especially distance from the access point/router. Moving the router closer to the HDTV(s) solved my issue, along with upgrading to a newer router that permitted the addition of a separate 5GHz network just for the HDTVs. Also try changing the router channel to the less travelled edges, at least experimenting as such.
I am certain the problem is not the Samsung built in wifi card.
Good luck.
I am hoping somebody can help me.
I have the Samsung KS8500 curved tv and when I am watching Nexflx in 4K the wireless drops off after awhile. I have had the service provider out to check there lines and everything checks out and the warranty service tech has replaced the motherboard and the wireless card and it is still happening. To get it back on I have unplug the power on the tv for about 5 minutes.
All my other products work and I can watch HD movies on Netflix without a problem.

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