For two reasons. Firstly, to align with the new Mongoose Marketplace brand. Additionally, around the same time Facebook reached out and specifically asked that their name be removed from the name of the plugin (and all other WordPress plugins).
Unfortunately this isn’t possible. Facebook have imposed a limit of 500px for the maximum width
The most common reason a page won’t display is when the page has audience restrictions. Make sure there are no age or location restrictions set in your Facebook page settings.
Another common reason is that it is being blocked by an antivirus, adblocker or other browser extension. Try disabling any antivirus or adblockers to see if that is the cause.
Firefox’s Facebook Container is also known to prevent the plugin from displaying.