Hi,
I upgraded my Kde Neon to the latest 5.20 and I lost the audio ("no output or input devices found).

I had the same issue with the previous upgrade and I fixed it with
sudo apt purge timidity-daemon

This time the trick didn't work.

Any suggestions?

Found the solution here:

https://www.linuxuprising.com/2018/06/f ... ue-in.html

Problem solved.

We're always having that problem since installing Neon earlier this year. Please offer options other than kernel-generic! That's often the problem. Whenever I add packages for kernel-lowlatency (may not be generic) and maybe generic extra modules, the problem is solved. The thing is, kernel-generic should *never* be the only option. If the Ubuntu programmers would just take a look at more long-time/oldest GNU/Linux operating system (OS) distributions (distros) or similar/older OS like actual Free/Libre/Opensource Software (F/LS, OSS, FOSS, FLOSS) Unix, they'd see that providing only generic is something that for a serious OS is just not done... of course, Ubuntu never tried to be a Unix rather than 'an Apple/Windows.'

The problem isn't related to Linux, the problem is related to Realtek as a company - They make garbage and they don't support Linux 'at all'.

Any driver you use to run Realtek hardware under Linux is a reverse engineered Windows driver provided by the community and is going to be buggy at best. The 'generic' kernel is generally considered to be the most stable under an LTS release for most general purpose configurations, Ubuntu offer a number of differing variants from lowlatency through to Azure and raspi2. Naturally it is not practical to use these kernels in a vast majority of cases - However the option does exist to use a kernel suited to a specific usage scenario.