Bug reports in KDE can be submitted at https://bugs.kde.org/
I'm not sure if the bug is in Powerdevil (the KDE Power Manager) or the Plasma Battery applet though. Filing the bug against Powerdevil would be a good start I think.

bcooksley wrote:Bug reports in KDE can be submitted at https://bugs.kde.org/
I'm not sure if the bug is in Powerdevil (the KDE Power Manager) or the Plasma Battery applet though. Filing the bug against Powerdevil would be a good start I think.

There was already an open bug report about it. I have posted a comment linking to this forum and the debian bug report I posted:

https://bugs.kde.org/show_bug.cgi?id=334321

I'm afraid this issue hasn't gotten much attention... also from the bug report, all the affected people seem to be using ASUS laptops, I find that puzzling, doesn't Upower handle keyboard brightness for ALL laptop at this point?

One possibility is that UPower is able to immediately detect keyboard brightness on all other systems but ASUS specific characteristics delay this recognition on those systems - triggering the bug you see.