Include the same range of events within map view as are shown in list view (ie, include events that are not associated with venues or that are associated with venues which lack geodata)

full-list-on-map-view.php

<?php
/**
 * Display the same range of events within map view as are shown in regular list view.
 */
add_action( 'init', function() {
	if ( class_exists( 'Tribe__Events__Pro__Geo_Loc' ) ) {
		$ecp_geoloc = Tribe__Events__Pro__Geo_Loc::instance();
		remove_action( 'tribe_events_pre_get_posts', array( $ecp_geoloc, 'setup_geoloc_in_query' ) );
	}
} );

/**
 * Only include map markers with geodata.
 */
add_filter( 'tribe_events_ajax_response', function( $response ) {
	if ( 'map' !== $response['view'] || empty( $response['markers'] ) ) {
		return $response;
	}

	// Remove markers which do not have geodata
	foreach ( $response['markers'] as $index => $marker ) {
		if ( strlen( $marker['lat'] ) === 0 && strlen( $marker['lng'] ) === 0 ) {
			unset( $response['markers'][ $index ] );
		}
	}
	
	return $response;
} );