Different dc results with Operating point analysis and DC Sweep analysis
I know it's late. I had the exact problem but I solved it. First thing you have to do is making sweep interval much smaller. This way you can get better results. Also, instead of checking points with 0.1 difference you should make it lesser like 0.001. When you do it as you did, DC sweep rolls up the value a bit and this a problem for delicate circuits. Smaller intervals+more point may be your answer.