Since OH3.0.0 i get an issue with percent value of a device. It’s a dummy device and the value will be set by a command. That works without problem. Now i if try to entry a unit for via state description the value will change to 100 times higher:
A Quantity type Item of type Number:Dimensionless is often used to hold a percentage value. But it’s not limited to % as a unit, it can also be expressed in dB or ppm … or a ratio. When, for example, you update a Number:Dimensionless Item with something like 0.46 - with no units - it will be assumed to be a ratio, 0.46-to-1. If you later read the value requesting %, you get 46%.
So you can see what’s going on here, your Item has a 59 value (with no unit) and when displayed as % that gives 5900%.
However, none of that should happen if your Item is really just a plain Number type, and not a Number:Dimensionless. That part I cannot explain.