Once again, I rendered out a bunch of clips for a client and found that Resolve put the wrong audio into a file.
Playing back on the Deliver page, the correct audio played. In the rendered file, the muted camera-audio track was used. Inexcusable.
Screwing around with the type of output ("individual clips" vs. "single clip") did not change this result. Finally I deleted the erroneous audio track entirely... only to get a silent resultant file.
Then I noticed the audio-track selector in the render settings, and figured I might be able to use that to force Resolve to do the right thing. Nope: It's totally broken. If you roll over it, the cursor turns into an inapplicable side-to-side arrow; then if you roll away, up/down arrows briefly appear... baffling. And if you enter a number manually (like 2, in this case) it just reverts back to 1 when the control loses focus.
Guys... this is not production-ready software: