Messenger Kids and Camera access suddenly not there

My child has had and successfully used Messenger Kids for over a year - camera etc. - on her iPad (new purchase at Christmas last year).

Now suddenly it says that she can't make video calls ("This feature requires microphone access. In Messenger Kids settings, turn on Microphone"). But when I go to Settings/Messenger Kids there is no where to click access to microphone (or camera for that matter). I do not have restrictions on and have double checked in "Screen Time" and "Privacy" etc but there is nothing I can click to give access. Any suggestions on what I can do would be greatly appreciated!