.

[fervent flame]

Have you turned on the option on top to let it always run in the background?

If too many things happen at the same time it can lead to it throwing a tantrum and not changing the refresh rate properly. Let it do it's thing once you unplug the charger or replug it without you doing or working on anything. Resume whatever it is after it's done doing the changes.

[toxic dirge]

Show your actions for when connected to power.

does the power mode and keyboard backlight change accordingly?

[toxic dirge]

do you have other actions that are interfeering or something? im not really sure