Like you said, it wasn’t Buddypress at all. It was the rtMedia plugin’s js file called “rtMedia.backbone.js” that had the on click function set to “false” for some reason. I changed that to “true” in row 756, and deleted this from rows 717-723:
//handling the "post update: button on activity page
jQuery( '#aw-whats-new-submit' ).removeAttr( 'disabled' );
jQuery( document ).on( "blur", '#whats-new', function () {
setTimeout( function () {
jQuery( '#aw-whats-new-submit' ).removeAttr( 'disabled' );
}, 100 );
} );
Just documenting this here in case other folks find their way to this through search engines.