I can't access the marketplace to update my texture packs to 1.20

Since the most recent update, every time i have booted up the game, the marketplace button has remained greyed out and said "Invalid session, try restarting your game" restarting the game does nothing, getting closer to the router in my house for better internet does nothing. I still very clearly am connected to the internet as my skin still loads and it usually doesn't when there is no internet, and we even got an updated router the other day and my system still won't let me connect to the marketplace. I would love to get this issue fixed so i can update my texture packs to the latest version and keep using them without having out of place textures.