Beginner question: Sound problem

I'm doing some simple editing of a recorded webinar, just cutting out all the gaps and awkward bits. I'm not a professional editor, I'm new to DaVinci Resolve, and I'm sorry if this is a really stupid question.

When I have marked the in and out points for my video and then added the selection to the timeline, the audio is being converted to mono. I can see how to switch it back to stereo on each clip, but I can't find the setting to make sure it stays stereo in the first place. The first few videos I edited didn't have this problem, so I've clearly accidentally clicked something I shouldn't have, but for the life of me I can't work out what.

I'm using the free version of DaVinci Resolve 16.2.8.005 on a Mac running Catalina.

As a new user, your first course of action should be to complete some Resolve training. The Beginner's Guide and Advanced Editing are an excellent groundwork to get you moving smoothly.

https://www.blackmagicdesign.com/produc ... e/training