That is a Ukranian defence news site making these allegations. It doesn’t give any indication of the “source” of such news.
Including a similar Turkish site, there are a number of other foreign sites that make the same news too. But none of them give the source of the news.
It looks like someone made the news piece, and everyone followed suit.
Reminds me of “Nasrettin Hoja” the Medieval Ottoman Comedian; who utters a lie at the beginning of the street we was walking on and believes the same lie when he reaches the end of the street and hears it; as it has travelled faster than him.
Can anyone give a credible source that corroborates this news?
All Russian websites publishing this information cite the Turkish newspaper Nefes as their source. Nefes cites an unspecified source. This story may be false. But it is interesting. Russia does have serious problems with air defense. The problem is that it has thousands of military installations in its vast territory that need protection from long-range Ukrainian drones. In Crimea, almost all of its air defense systems, including the S-400 and even the “legendary” S-500, seem to be out of action. (All Russian weapons, from Kalashnikovs to T-72s, are legendary

) Even with their vast front line, they have a serious shortage, not to mention the thousands of installations, including strategic ones, that need air defense in the rear. The claim that they want to buy S-400s from Turkey and sell them to India is a myth for the truly naive.