Unknown application message on screen

Hello,

I own an iPhone 8. Yesterday, while I was having a call with a call centre (automated voice/digit in sort of thing), this weird message appeared on full screen saying ‘Unknown Application”, as shown in the attached picture. One more weird thing: I was using the iPhone earphones to make the call, when a brief interference/electronic sound came into the earphones basically at the same time when the message appeared. Maybe the two things are not related, but it was all really strange.

I couldn’t take a screenshot because I pushed the home button and got back to home.

Any idea on what happened? Is there anyone who experienced something similar out there?

Thank you,

mat

Disclaimer: I found the picture on another post in this community, so it’s not mine, but it looks exactly the same to the one I saw on my screen, except for the language of the button which was in Italian. Couldn’t take a screenshot of mine.