Trouble with hdmi connection

Infuse 3 pro works fine when watching a film on the iPad, but when I connect the iPad to an hdmi connection (so as to project the film on a screen) it simply doesn’t work. The screen turns 90 degree, and the image is fixed. The problem is not the connection, because other apps work fine.
Please, help me solve it. I’ man teacher and being able to project video in class is so important for me.
Thanks.