Russia's ongoing invasion of Ukraine has had an enormous impact on studios and independent developers anywhere near the conflict. Stalker 2 developer GSC Game World was based in the Ukrainian capital city Kyiv, but is currently in the process of relocating to Prague, and in March ceased all operations in Russia.
GSC has since the start of the war condemned the "inhuman cruelty" of the invasion and been explicit about this being a question of survival for its employees and their families. The studio has paused development on Stalker 2 for the moment—though did update the Steam entry to change the word Chornobyl to reflect the Ukrainian spelling). The game's official website was also updated with a message of support for Ukraine and a link for aid donations.
The latter gesture may seem relatively minor in the context of an ongoing war in Europe, but not if you're the Prosecutor General's Office of the Russian Federation (thanks, xgp). As reported by the Ria Novosti news agency, a state-owned Russian outlet, on March 18 the Russian authorities demanded that access to the Stalker 2 website be restricted in Russia, in a tit-for-tat move that may also be linked to GSC's decision to cease operations in the country.
To western eyes it may seem petty beyond belief that the Russian state has time to bother about the website for an upcoming videogame, but this is very much business as usual for Russia. The Roskomnadzor is a state agency that censors mass media, essentially, and manages a register of 'banned' sites that any company operating in the region has to abide by.
GSC Game World has not commented on the situation. The studio's most recent activity was a charity sale of its games that by mid-April had raised over $800,000 to be donated to the Come Back Alive charitable foundation.