JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr = [1, 2, 3, 10, 5, 11, 12, 2, 4, 25],
    nonvalid = [],
    lastGoodValue = 0;

for (var j = 1; j < arr.length; j++) {
    if (j && arr[j] <= lastGoodValue) {
        nonvalid.push(arr[j]);
    } else {
        lastGoodValue = arr[j];
    }
}

console.log(arr, nonvalid)