In the Java edition the cursor recenters to the middle of the screen when your done using the inventory UI. The Windows 10 edition has the cursor appear where you last had it, meaning if you left it in the top right corner, it stays in the top right corner.

Not only is this a small but huge difference between the Java and Win10 version but Its also annoying to figure out where the cursor went EVERY TIME you go into your inventory. This needs to get patched.