Are you still in contact with your dietician? Might be worth a conversation with them to see if there’s something you’re missing & to get you back on track. Maybe track your food for a week or two as well if you don’t. Can be easy to get a bit complacent about portions, ingredients, etc. as time passes. You could take this data to the dietician too. Have you see your surgeon recently?
PS: Can you provide a little more information: type of surgery, starting weigh, weight lost, current weight, how long you’ve been plateauing, etc. It’s very helpful when offering any advice or suggestions.