That explains it - we’ve been looking in to this issue impacting our Russian players, but it shows to be the result of Roskomnadzor activity, as we’re aware that this issue is occurring outside of Darktide and in other online products and services too.
We’ll share any updates on the case here:
Additionally, the comments here from a couple of our Russian players explain the workarounds they’ve used, which may be of interest to you:
https://forums.fatsharkgames.com/t/error-signing-in-backend-error/108663/5
I should add that the restrictions appear to be slowly being removed across the country, so I hope you’ll soon be able to play.
Alternatively, I can assist with a refund should you prefer to take that option.