Accidental Silent Mode
This is not really a question, any more. Found a hint in previous thread relating to this and was able to reproduce problem by squeezing Otter case next to Silent Mode switch on my IPhone 11, which actived Silent Mode unintentionally. Did not have this problem with previous iPhones and cases. Just posting to help people since this is a continuing possible problem, but not a settings or software issue.
iPhone 11 Pro