Trying to get SEA-CDG-BLR on Comfort+ Aug 06-14, 2018
delta.com shows options/fares for main cabin and delta one. Premium select shows "not offered". Seats show the flight has Comfort+ with lots of seats available.
Main cabin fare price is a little higher than usual but fare basis are still in the lower/mid (Q~T range). Regardless, there's no ability to purchase c+ upfront. So is that a delta.com bug or is it intentional by Delta to save c+ seats for diamonds/platinums?