Hey guys, I have an update for ya.
After profound testing we can confirm that issue. But sadly, Corona have no control over this type of audio mute, made by Appodeal SDK. So I went to fellow Appodeal SDK developer and we’ve investigated an issue with him. More of not-so-good news - Appodeal have no control over it too, since it’s just an ad mediation service and the issues comes with a specific ad provider SDK.
We’ve narrowed down android issues to admob (but it’s very inconsistent, I haven’t seen an issue on my devices, for example, so qa team still working on it), for iOS the issue comes from IronSource for sure. Appodeal team are discussing an issue directly with these ad providers, but no estimated for a fix. But since they are aware of this issue, I’m sure the fix should be available asap.