Why these variables do not work from cnf configuration file?

I am trying to set these variables by entering them in mysqld.cnf file on my percona cluster machines but they don’t work. Mysql daemon errors out if I have the following parameters in the file. The only way to implement them is through SET GLOBAL directive on a dynamic basis.
According to the PMM manual, I should be able to do it
Can anyone explain, what I might be doing wrong? Is mysqld.cnf correct file for these variables?

mysqld.cnf is most likely not correct file for configuration

The best way is usually to create separate file, such as pmm.cnf and put it to the /etc/mysql/conf.d/ directory