Hi,
Welcome to share here!
If the power plan can't be changed for all the domain joined clients or part of them , it may managed by the domain group policy .
I would suggest you check the group policy settings by the following command :
Run CMD as administrator and runt he command :gpresult /h report.html
Then ,check if power plan related settings in the report.
If yes, you can find the settings was deploy on which GPO .
Best Regards,