Cartouche inversée universelle à valve thermostatique 47282000

Was NOT able to install the cartridge properly. When I turn the black temperature control nut clockwise it would push the piston past the O ring into the cartridge and water would escape through the hole in the black nut. The temperature probe of the new cartridge is much shorter than the original but I don't think it should made a difference with the leaking issue. Do I have the correct cartridge?

My shower valve body was installed upside down and this cartridge was needed to make it work. Was a lot easier than reinstalling the entire valve body!

As the buyer only, I can say that the plumber had no trouble installing it and he knew the GROHE brand very well. He said it is top quality.

The cartridge is not manufactured correctly the splines for the stop ring are missing. all the pictures show the cartridge with these splines but the "technical" rep refused to believe me that they are needed for it to work. Totally frustrated