I recently installed a K3 on my 2023 KTM Super Duke R Evo. I bought a couple of Samsung ProPlus 256GB microSD cards from Amazon. I tested them to ensure that they weren't fakes (all too common these days) and benchmarked them; everything checked out. However, after installing and formatting in the K3, I was getting zero size video files and some larger corrupted video files. I tried with both the new cards.
I then bought a SanDisk Extreme Pro 256GB card and it works fine.
I don't know if I was just unlucky with the Samsung cards (which, by the way, are working fine in a different application), or if there's some incompatibility. If anyone else has this issue, I hope that this post helps,
I use cards from the Samsung Evo series, they work fine. They are cards of the maximum storage that the cameras can handle. I do make sure that I format the cards in the Innovv cameras using the App.
You may have been unlucky with the ProPlus cards.
I mainly use SanDisk SD Cards, but also have a few Samsung SD Cards, which I sometimes use in my K3. No problems so far. But they are all 128GB, not 256GB.