Keep your eyes open when shopping on AliExpress. This device was supposed to be an RF 50-Ohm power splitter. With 51 Ohm resistors in a star configuration it’s a 153 Ohm system power splitter, not a 50 Ohm one. Instead of 51R there should be 16.67 Ohm (or close to) resistors.
and so on.
So far I have found only one correct item with a star configuration and 16.5R: https://aliexpress.ru/item/1005002517540493.html
Another working alternative is to use triangle configuration (with which Chinese developers seem to have more luck): https://aliexpress.ru/item/1005001273710257.html