I setup Sleep mode and needed to allow some calls so I added the contact to the "Allow during Do not disturb" list. However the call was still muted and I missed the emergency call out. I tried the alternative of setting a favourite and that works as expected the call gets through - but that's annoying as I don't want to favourite those contacts as I don't call them (they call me).
I'm guessing it's a bug - possibly because the specific contact has maybe 200 mobile phone numbers including all possible support line numbers?
I did chat support who asked me to reset all settings and restart in safe mode for a few hours but that's a massive pain as I'd have to reconfigure everything on my phone again - and not something I can do until I'm not on call for a few days. Also every time I've reset all my settings in the past it's never fixed a thing... but I feel nervous about the issue unless the "workaround" is confirmed by someone who understands the issue.