Brightness issue on Lenovo Yoga Slim 7

I’ve got an issue with Fedora 33/34/35 Silverblue on IdeaPad 5 15ARE05 (Lenovo Yoga Slim 7) and brightness and wondered if anyone can help both:

  • Confirm the issue is happening on their Yoga Slim 7 too?
  • Help try to fix the issue?

The function keys for brightness work on both power connected and disconnected.
The brightness slider works in the Gnome menu on both power connected and disconnected.

The issue I have is that:
(The brightness values are from the command “cat /sys/class/backlight/amdgpu_bl0/actual_brightness”)

Using Gnome slider in menu:
After reboot brightness is at 128, if I plug the power cable in the screen dims to 20.
If I unplug the power the brightness stays at 20.
If I use the brightness slider to go to 128 then plug the power cable back in it then stays at 128.
Subsequent power cable connections and disconnections the brightness stays where it should be.

Using Fn key and brightness keys:
After reboot brightness is at 128, if I plug the power cable in the screen dims to 20.
If I unplug the power the brightness stays at 20.
If I use the fn keys and brightness to go to 128 then plug the power cable back in it then stays at 128.
Subsequent power cable connections and disconnections the brightness stays where it should be.

Using power cable connected and Fn key and brightness keys:
I’ve also tried a reboot with the power cable connected, brightness is at 128, if I unplug the power cable the screen dims to 20.
If I plugin the power the brightness stays at 20.
If I use the fn keys and brightness to go to 128 then it and unplug the power cable it stays at 128.
Subsequent power cable connections and disconnections the brightness stays where it should be.

  • It appears there is an issue with brightness and the first time the power cable is plugged in or removed??

I’ve had this issue on the last 3 releases.
Any help would be very much appreciated.