Mine from that source is working fine and others report good results too. I tested mine first. Down 30 lb in three months at 1800 calories, current weight 282, age 46. I track carefully and usually round intake upward when I cannot measure. Work keeps me on my feet but I am not doing extra exercise. Everyone responds differently and I lean toward using the lowest effective amount.
That source is usually reliable. Did you tighten up the calorie tracking? My own scale has been moving oddly the last month, probably just from getting lax.