Grid Legends won't connect to your servers on console "X Box"

When you have selected all the add-ons, make sure you scroll down in the menu, because some are hidden !!

If nothing works, then select to remove that whatever part, (it's sad it doesn't specify which part they're on about on the initial screen you get when you start the game), of the game that is missing and continue, obviously don't select to delete everything that's saved, because you'll have to start the game allover again, I think afterwards, when the game does start, it will show what was not being recognised before in the add-ons you'll see where you can buy them in the shop, which is or not installed, and since you own all add-ons, they'll still be yours to add-on later, but you'll  have to redo that part of the game progress, that's what I'd go for, it's not a big loss, not as much as losing all the game saved progress...