Remove events from a specified event category in "The Events Calendar" by Modern Tribe

functions.php

<?php
/**
 * The Events Calendar Remove Events from Month and List Views
 *
 * @param  [object] $query Query of the events page.
 * @return [object]        Modified Query
 */
function tribe_exclude_events_category_month_list( $query ) {

	if ( isset( $query->query_vars['eventDisplay'] ) && ! is_singular( 'tribe_events' ) ) {

		if ( 'list' === $query->query_vars['eventDisplay'] && ! is_tax( Tribe__Events__Main::TAXONOMY ) || 'month' === $query->query_vars['eventDisplay'] && Tribe__Events__Main::POSTTYPE === $query->query_vars['post_type'] && ! is_tax( Tribe__Events__Main::TAXONOMY ) && empty( $query->query_vars['suppress_filters'] ) ) {
			$query->set(
				'tax_query',
				array(
					array(
						'taxonomy' => Tribe__Events__Main::TAXONOMY,
						'field'    => 'slug',
						'terms'    => array( 'filmtournee-unterwegs' ),
						'operator' => 'NOT IN',
					),
				)
			);
		}
	}

	return $query;
}
/* 
I've found several versions on the internet but there aren't working for me, so I digged a little deeper 
and found the culprit: the priority needs to be above 50 to work as there are using priority 50 themself:
https://github.com/moderntribe/the-events-calendar/blob/c0128a69b600d6c279952e0ac7b6aea22d2028bb/src/Tribe/Query.php#L42
*/
add_action( 'pre_get_posts', 'tribe_exclude_events_category_month_list', 51, 1 );