The NEMA 14-50 is supposed to fit tightly into the 14-50R. The 14-50 receptacle is not like a standard 5-15 receptacle that is able to withstand thousands of plug and unplug operations. Best practice would be to leave the Tesla Mobile Connector with 14-50 power plug adapter plugged in and only rarely unplug.
(Also, make sure the Mobile connector is not left hanging only supported by the power plug. Tesla sells a Cable Organizer that includes a wall bracket for the Mobile Connector. Similar organizers are available on Amazon, eBay and Etsy. You can also fashion your own hanger for the Mobile Connector.)