Log In and Purchases

When I try to log in it takes me to a website for Xbox which then redirects me to the Microsoft log in but when I enter my information and log in it takes me through the same process again and then shows the minecraft loading screen and when I get back to the game it has deleted all of my purchases. I have had to purchase the same thing 3 times and it keeps making me repurchase everytime I try and log in to my Minecraft account.