Cannot select correct input device in Davinci Resolve?

I am using Davinci Resolve for video editing with voice over (basicly followed this tutorial: https://www.youtube.com/watch?time_continue=10&v=BUVHBdcQRmk).

As input source there is only "ALSA" shown:

But I can't record my voice with it. Its just ignoring my microphone completly:

I only have this one audio input (Scarlett Solo USB):

The microphone works fine with any other software I tried so far. Do I need to configure some settings in Davinci Resolve to make my microphone work?

I have posted this question also at https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=91055&p=0&e=0&sid=bf1570e0bb877f4cbc3baf75edfc67e1

Solution 1:

With the newest update 17.4. and Ubuntu 21.04 it works.