Can't see properly my Smartphone while sharing the screen

Hi.
I'm working in a classroom and I wish to show my students some of my Smartphone's applications. I work with a computer that is attached to a projector. After starting a meeting in Zoom on the computer, I send an invitation to my own Gmail account and I open it on my Smartphone. Then I share my Smartphone's screen. I want to show the Smartphone's screen by using the computer and projector. The only thing that is shown is my account photo. Although I enter an application on my Smartphone, the projector doesn't show it.
Not long ago it worked fine. What am I supposed to do to share the screen properly?