I believe championship is broken, although there. For me, the left portion is a strange milky colour, the calendar can't be changed and the cars are (although it can't be seen on the championship screen) the 2020 Stock Car Brasil cars.
I've got to agree, with only a grid of 12 as far as I can tell too. There's a difference between WIP and alpha state, or even a proof of concept which this barely qualifies as. I trust Reiza to implement it properly and I understand why that hasn't been done yet, but that wording is a bit disappointing.
I guess championship mode will be all the better when it arrives, hopefully with the custom rosters, drivers and liveries that Reiza has mentioned too.