That's considered a stall. Plateau's are generally when you are close to your lower limits and you get stuck there pretty much forever, so let's hope this isn't a plateau.
Are you tracking body fat % as well? Are you working out? Bodybuilding/weight lifting? What's your daily intake vs burn look like? Are you tracking intake? Hows your water?
Something VERY important to factor is your BMR. Basal Metabolic Rate, the amount of calories you burn in a day just by being alive, think in a coma, alive but not moving, that's your BMR. BMR drops as you get older and it drops as you lose weight. https://www.active.com/fitness/calculators/bmr
If I assume you are 6 foot, starting weight of 408, starting age of say 35 would put your BMR at 3285 calories per day. Dropping that 408 to 330, with the same height and age, drops that BMR to 2799 calories per day. That's just shy of 500 calories less burn per day now. So, you can see, as we get older and thinner, it keeps getting harder to maintain the same speed of weight loss. We need to either increase our exercise or decrease our caloric intake, or both.
Hope that helps some.