Ubuntu 20.04 on a Thinkpad X1. Simple problem: the audio-muted led, on the audio-mute fn-key, is suddenly not working, although the audio-mute key is working normally (audio-mute, not mic-mute). I would just like to check if this is a hardware or software issue. How can I check this?
Some Q&A on askUbuntu about this are quite old (e.g. this, whose answer doesn't work in my case). Others, like this, have never been answered (TBH I doubt this will be answered either...).
