I tested Samsung 128GB 100MB/s (U3) MicroSD EVO Select as well on my Samsung S8 plus and my Samsung Tab S3 (Internal storage to SD card and SD card to Internal storage). I tested filming in 4K and transferring 4K content for about 45 minutes without any hick-ups. I have no dealings with Samsung in any way shape or form.
https://www.amazon.com/Samsung-MicroSDXC-Adapter-MB-ME128GA-AM/dp/B06XWZWYVP