I also have the same issue. Called Samsung and although very sincere on the phone, kindly told me that since the TV is just out of warranty they wouldn't be able to assist. My suspicion is that there has been a software update to fix a security vulnerability and part of the patch has now blocked any access to the NAS from the TV. Interestingly enough, I have an older Samsung TV (running an older OS, not auto-updated) and this still see's the NAS perfectly.
So it looks like anyone who wants to connect a NAS may need to steer clear of Samsung and throw away perfectly good TV's, all due to inadequate coding of a software update. Please resolve this Samsung!
That is messed up. I always have my external HDD hooked up directly to my Samsung TV and never connected it to the internet. Because several video files were unable to be played by the TV, I decided to update it.
Not only are the files still unable to be played, the worst thing is that now the Smart button doesn't show the option to view the recently played videofiles anymore and I now have to manually search through my entire harddrive in order to continue watching a video I started.
It seems Samsung is trying to dissuade users from watching content from their harddrives and is trying to force them onto the online subscription platforms.
Anyway, this is the last time I will be buying a Samsung TV if they are restricting us consumers to use the product as we want to use it.
I hope you get the NAS to work again but I have given up hope being able to use the recently viewed option again and severely regret updating the ***** TV.