When I wan't to open Marketplace, the game says it is an invalid session.  My skins in Dressing room also don't show up.  

Expected result:

I can open Marketplace and I can choose my skin.  

Actual result:

When I click on Marketplace, a texte appears that says: 'Invalid session (try restarting your game).'  

Also, if I want to change my skin.  The skins in Dressing room don't load.  

I have tried restarting my game and I have even reinstalled it.  It doesn't work.  

I noticed this bug before (1.18) and I didn't report it, because I hoped it would be fixed in the next update.  

I also have Minecraft on my phone, but there is no problem there.