No Russia is not officially on gold standard.
To be on gold standard country has to use gold as fixed unit of account by setting fixed exchange rate between currency and gold, and be willing to exchange the currency for at the promised rate (see Eichengreen & Esteves (2021), International Finance in The Cambridge Economic History of the Modern World: Volume 2: 1870 to the Present, Cambridge University Press, vol. 2, pp. 501–525). That exchange rate can be devalued or revalued in the future, but you can't have gold standard when there is no fixed exchange rate between gold and currency in some given time period and the price of gold (in the currency you want to turn into gold standard) is allowed to float.
However, what Russia has done is sort of an inverse gold standard. They did fixed the price of gold in terms of rubles, but you are not allowed to exchange your rubles for gold. There is quite good Al Jazeera article that explains the difference in detail here.
Hence technically they are not on gold standard but rather they instituted 'gold peg'.
Likely Russian propaganda calling it 'gold standard', and the fact that it indeed sounds like a gold standard (it almost even is, if Russia's central bank would be willing to give you gold for rubles it would count) confused many people and even media.