Thanks for reaching out. Does Game Mode turn off every time you restart even after enabling it in Settings?
Go to Settings > Gaming > Game Mode and make sure it’s set to On. Then check for any Windows Updates under Settings > Windows Update, as newer updates include fixes for Game Mode. Also, confirm you’re signed in with your Microsoft account since some gaming settings sync with your profile. If it keeps resetting, run the Windows Store Apps Troubleshooter from Settings > System > Troubleshoot > Other troubleshooters to refresh system gaming components.