Magic Tracpad stuck in clicked position

Make sure that it is on a flat surface.

If it is stuck, take it to your local Apple Store or AASP and have it checked out.

Genius Bar Reservation and Apple Support Options - Apple

Believe it or not, a very common cause of this is a corner or edge of the trackpad getting hooked under the edge of a keyboard or other object on the desk. I've had this a couple of times.

Easy enough to check.

Turn Trackpad off and on with switch on trackpad.

Please restart the computer.