Did you, perchance, download a Dolby Vision version of the title unintentionally? Samsung created HDR10+ (note the plus) as an HDR10 (no plus - this is the industry standard) compatible answer to Dolby Vision. Since HDR10+ is a Samsung thing, and is positioned as competition for Dolby Vision, Samsung TVs only support HDR10 and HDR10+.
You can check if the file is DV rather than HDR10/HDR10+ a number of ways. The easiest, though, is to try playing the file in a software media player in whatever OS you use. Make sure the player doesn’t support Dolby Vision (most don’t, since Dolby Vision compatibility is licensed for money). If the video’s colors are all off and mostly appear purple and/or green, then it’s Dolby Vision.
