When I open Minecraft, it automatically logs me out and it says my Password and Email were incorrect, even though I made sure it was. I even tried copy and pasting it, but none of them worked. I had to restart my computer and Minecraft 4 times for it to let me log in, and after that I had to login again to make sure it doesn't say "Invalid Session (try restarting your game)" upon joining Hypixel.
I have the same problem when logging into my games too. If you exit the game then try again it could work. If you are on a computer shut it off. If you are on a mobile device shut it off or restart it.