This is by no means news. UOKIK tested such extension cords, it turned out that the cable has a cross-section of 2x0.14 mm?, which may cause a fire when a more powerful receiver is connected. Unfortunately, all the equipment bought "from a Chinese" (once it was bought "from the Russian") is not able to be controlled.
Besides, it happens that in construction stores it is common to find Schuko sockets. In one of the reports of the Office of Competition and Consumer Protection, the extension cord with the Schuko plug and sockets was withdrawn because "according to PN, the type of sockets and plugs used in Poland is the French type". If I had the equipment brought "from Rajch" or Ukraine, I can't buy an extension cord for it in Poland?