Update, someone has reported the same on console PS - https://answers.ea.com/t5/Bug-Reports/No-Attack-or-Transport-for-Renewal-defense/m-p/11624006/highlight/false#M18171
So the only people able to select vehicles must be people who join later in the game, in the next sectors...
Honestly this update is absolute trash for so many reasons, it's essentially reverted the game 3 months back.
Just fully revert the update, at least people were able to somewhat enjoy playing before this dumb update.
Having this issue also when youre playing defense on Breakthrough.
Just experienced it again on Exposure Breakthrough. If you joined in the first sector you only see the first sectors vehicles in sector 2 & 3.
