Hi, If PL is changing the defaults, then there probably is a process or feature/option set up to run a specific power plan (normally BHP power plan).
1) First, you can alter default power plans either right click on PL tray icon >active power plan or from the main menu of PL. Note this is the same as going to control panel and changing default power plan, this should stick except for the below options.
2) Open menu options>performance mode and uncheck BHP power plan if you don't want that plan with high workloads.
3)Also, do the same for configure application power profiles if you added any, edit the plan if not default.
4) If you are using Idlesaver, make sure the proper power plans are set that you want.
5)If rare case BHP is not best and somehow is conflicting with AMD software or power plan, you can uninstall BHP power plan. You can always install it back easy too. There is an option toggle for that in menu >options> performance mode options.