Confusion with grade boundaries and the grade shown on my paper

https://preview.redd.it/o867czonq7ng1.png?width=1577&format=png&auto=webp&s=eebdea9ce88469f73822730e8972e18cba0dbdf2

Hello everyone! So I got 90/100 UMS on economics unit 3 business behaviour, and the edexcel grade boundaries say that's an A*, but my statement of results says it's an A as you can see here. I'm a little confused as to why there's a difference between them, but hopefully I'm not the only one with this problem! Does anyone have a reason for this?

https://preview.redd.it/c72kdz87q7ng1.png?width=1115&format=png&auto=webp&s=e6f8953b02a5acdf3811a8f2f7630e9ad6bb0650