On January 16, The Callisto Protocol stopped selling on Steam to residents of Russia. Neither the publisher Krafton nor the developers from Striking Distance Studios have publicly announced the suspension of sales, but the page with the game no longer opens in the region.
At the same time, other Krafton games — PUBG and Thunder Tier One — are still available on Russian Steam.
Update from 19.01: The Callisto Protocol has again become available for purchase on Steam for users from Russia.