Cut a piece of tape/ paper approximately the size of your Sim Card and secure it to the back side of the Sim. Be sure to trim any excess.

It's important that you place the tape on the back side of the Sim Card as it will block the communication with the device if placed on the front side

Slowly slide the Sim Card tray back into the device. It should be a smooth transition, don't force the tray in.

If the tray is still loose you can keep adding tape/paper until it's no longer loose.