You might be using a default class other than TS. For example, your system might be running a window environment that uses the IA class by default. You can manually move all processes into the FSS scheduling class without changing the default scheduling class and rebooting.
For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.4.
$ priocntl -s -c FSS -i pid 1
$ priocntl -s -c FSS -i all