This may be intended, but I think it's a bug.  If I hit I for inventory, but I was trying to get to something else like the tech tree, I could click the button that looks like a house to the left of the inventory screen and it would take me to the home page where I could select from inventory, tech tree, knowledge, radar, etc.  Now if I hit the button it just closes the menu out completely.  So whether I hit the back arrow above it or the home button they both close out the window since the latest winter update.  I always hit 'I' for inventory out of habit and liked the old way better where I could navigate to the home screen without having to close the window out and then hitting tab to open the window again.  
             
            
            
            
                
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