Roku output alternates between 59.94hz and 60.00hz
I’ve notice this on my 2020 Ultra and 2021 4K stick. Both Rokus will randomly switch their output between the correct 59.94hz for NTSC televisions and a flat 60.00hz. This usually happens when switching between SDR and HDR/Dolby Vision, but you can also make it occur by toggling the TV type in the settings a few times. There’s no rhyme or reason to when it will switch the output, so it’s fairly random. The majority of content is23.976fps, which isn’t as smooth when the device outputs a flat 60hz. Here’s 2 photos showing the difference from the same device. It doesn’t matter if one as SDR and the other is DV, as both modes alternate between 59.94 and 60.00hz.