Google "three week stall." That is what is happening. Just stick to your plan and the weight will come off.
Nothing about post-op weight loss is linear. It is full of periods of loss, followed by longer periods of stall. That is just part of the process. Also, it is slow. I started my six month insurance-required diet program at 397 pounds, and weighed 298 pounds on surgery day. Even at that size, my loss in the first four weeks post-op was far from "dramatic."
But I have followed my plan religiously every single day, kept my carbs below 20 every single day, tracked everything I put in my body every single day, and even with the countless stalls, I have lost 205 pounds and am 12 pounds from goal at 9 months post-op.
Put the scale away if it bothers you and keep focused on what is important.
Good luck!