Sim card entrance

This is correct. There's nothing wrong with your iPhone XR.

In newer iPhones the sim tray cutout is inverted, and the sim card gold contacts need to face up to connect with the internal sim port.

On older iPhones the tray is designed for the sim card's gold contacts to be face down, because the connector is on the back of the iPhone, rather than behind the screen.

I don't understand what you mean about the sim card entrance being reversed. Could you elaborate?

Are your other phones iPhones? The SIM card tray works the same on all iPhones.

Go to Settings > General > About > Model

If it shows a number starting with an A tap on on it and post the number here.

And the model number?