I just bought SM-G781U1/DS from samsung US website. According to its model number is it a dual sim, but it doesn't work at all, no sim manager either. I hate misleading information, and I'm very upset with my purchase.
Samsung please do something about it and update your firmware ! The whole point of buying an unlocked phone is to be FREE.
I feel your pain. I purchased a Z Fold 2 and was also mislead to believe that it was a dual sim phone. I would use the Esim and a single physical sim according to the marketing. When I got it it didn't have a sim manager in settings so I contacted customer service and they assured me that Samsung would be pushing out an update which would enable this in the future. Here I am going on a year with this phone and still no update. I feel ripped off! I expected better from a company like Samsung. I too have been very loyal for years, but at this point I am seriously looking for other manufacturers phones.