Preconfiguration for cpptest Professional Eclipse Plugin custom compiler setting not working

In tried to preconfigure the eclipse Plugin settings with the parasoft.ini file.
The documention https://docs.parasoft.com/display/CPPTESTPROVS20212/Configuring+Localsettings shows that i have to set the custom.compilers.dir=[Directory]. But it does not set anything in the Parasoft|Configuration|Customs Directories|Custom compilers

"User Configurations and User Rules" works as expected. The value will be set with the values from the parasoft.ini file.
I tried to name the var (cpptest.custom.compilers.dir=[Directory]) in the case the other two do, but this also does not work.
Which one is right?
1) custom.compilers.dir=[Directory]
2) cpptest.custom.compilers.dir=[Directory]

Maybe someknows what is wrong here.