microphone Iphone X R

For several days, after updating the IOS, my IPHONE XR no longer sees the guitar and the phone’s microphone is always active.

HELP

if the audiointerface is not selcdtable within the app, your audio interface is not recognised by iOS.
Have your tried restarting your iphone?

Yes, I’ve tried it more than once. The strange thing that before the IOS update worked very well !!!
Thanks for your help Paul.

make sure you have the latest version of MIDI Guitar from the appstore: the old version is not compatible with iOS 12 and higher.

so our app works but you have only the microphone as input?