I upgraded from an S8 to a U2 on launch and have been wearing it since. I recently noticed a red area on my wrist directly under the sensors. It doesn’t hurt, burn, or itch. My skin isn’t raised and feels normal to the touch. If you look closely the skin is “scaley” (and red, of course). Anybody else notice this?
Swap wrists until this healed. After it healed, start swapping wrists for sleep. This is due to chronic moisture exposure.