The unique spare parts for Boeing supposedly manufactured exclusively in Russia, were reported on by "Trendy" program on Belarus 1 TV channel on May 22, 2024.
"The heat exchangers are the mechanical part of the system. They are produced in Russia. After the US imposed sanctions against Russia, the export halted. It turns out that no one else makes them on an industrial scale except for the sanctioned Russian Federation" – reported the program.
Google search for "heat exchangers for Boeing from Russia", brings up the American The Wall Street Journal newspaper. An article about these parts was published by the paper in early May. Apparently, that's where ATN sourced their information. But got it all wrong.
Russia does not manufacture unique heat exchanger units for Boeing. They are made by the American company Raytheon Technologies Corp. who had a joint venture in Russia called "Hamilton Standard-Nauka".
In March 2022, after the full-scale invasion of Ukraine, the American company closed down its Russian facilities and moved production of these parts to its factories in the United States and the United Kingdom. The orders were low and manageable at first. But after a while the demand outgrew production.
Which means that the sanctions disrupted the established supply chains for the Boeing heat exchangers.