Context not working for custom fields

Adding the event ID in context does not make the custom fields appear on the indicated event add to cart form. Instead, it removes it entirely.

This is how I had the code:

add_filter( 'mt_custom_fields', 'create_custom_fields', 10, 1 );
function create_custom_fields( $array ) {
	// Other fields: sanitize callback; input type; input values; display_callback
		$array['golf_partners'] = array(
		'title'=>"FOR GOLFERS - Golf Parnters:",
		'sanitize_callback'=>'sanitize_callback',
		'display_callback'=>'display_callback',
		'input_type'=>'Text',
		'context'=> '2',

		
	);
	$array['game_choice'] = array( 
		'title'=>"FOR GAMES - Choice of Game", 
		'sanitize_callback'=>'sanitize_callback', 
		'display_callback'=>'display_callback',
		'input_type'=>'select',
		'input_values'=>array( 'None', 'Bridge', 'Mahjong', 'Canasta' ),
		'context'=> '2',

	);
		$array['game_partnerss'] = array(
		'title'=>"Game Partners:",
		'sanitize_callback'=>'sanitize_callback',
		'display_callback'=>'display_callback',
		'input_type'=>'Text',
		'context'=> '2',

	);

2 is what’s listed as ID in My Calendar events.

If I remove the context line entirely or replace the 2 with ‘global’, the fields show up on all tickets pages.