mirroring issue

Recently i have started facing a problem while casting my i phone 11 pro to my android tv through miracast.earlier there was no such issue. The problem is that when the phone is connected to the tv, the vertical display of the screen appears stretched & full screeen. earlier the picture appeared in the centre of the screeen & not stretched. I am facing difficulty in doing whatsapp call and even seeing you tube as the picture is stretched in all left right 180degree angle.

I connnected my android phone to the tv and found out that in that case the picture is normal like in the middle of the screen if vertical and if horizontal then full screen. this means there is something wrong with the settings of the iphone.

can any one help me to sort out this issue. i will be obliged.