Microphone not working on iPhone or IPad - not fixed with update. Please help.

I’ve seen a few posts about this issue.

-Tried and checked settings for all Zoom troubleshooting steps, nope all in order. 

-Re-installed latest app. Also re-started several times after. Re-re-installed and re-started. 

Dead mike continues! No recommended fixes working so far. 

Can anyone else help with other Apple mobile fix experiences?! 

Hugely impacting on my work!