Custom FacetWP dropdown not showing posts - filtering

Question

I have been able to render a dropdown facet in FacetWP front end with:
add_filter( 'facetwp_facet_html', function( $output, $params ) {
if ( 'today_or_month' == $params['facet']['name'] ) {
$selected = isset( $params['selected'] ) ? $params['selected'] : '';
$output = '<select class="facetwp-dropdown">';
$output .= '<option value="">Select date range</option>';
$output .= '<option value="today"' . ( 'today' == $selected ? ' selected' : '' ) . '>Today</option>';
$output .= '<option value="month"' . ( 'month' == $selected ? ' selected' : '' ) . '>This Month</option>';
$output .= '<option value="test"' . ( 'test' == $selected ? ' selected' : '' ) . '>Test</option>';
$output .= '</select>';
}
return $output;
}, 10, 2 );
All 'event' posts show under the Facet dropdown on page load but when I select an option from the dropdown the queries do not return any posts in the FacetWP template. When I select "Select date range" again all the posts show again.
The queries are as follows:
add_filter( 'facetwp_query_args', function( $args, $class ) {
if (!isset($class->http_params['get']['facetwp'])) return $args;
$selected = $class->http_params['get']['facetwp']['today_or_month'];
$current_month = date( 'Y-m' );
if ( 'today' == $selected ) {
$args['meta_query'][] = array(
'key' => 'event_date_start',
'value' => date( 'Y-m-d' ),
'compare' => '<=',
);
$args['meta_query'][] = array(
'key' => 'event_date_end',
'value' => date( 'Y-m-d' ),
'compare' => '>=',
);
}
elseif ( 'month' == $selected ) {
$args['meta_query'][] = array(
'key' => 'event_date_start',
'value' => date( 'Y-m-01' ),
'compare' => '>=',
);
$args['meta_query'][] = array(
'key' => 'event_date_end',
'value' => date( 'Y-m-t' ),
'compare' => '<=',
);
}
elseif ( 'test' == $selected ) {
$args['meta_query'][] = array(
'key' => 'event_date_start',
'value' => $current_month,
'compare' => 'LIKE',
);
}
$args['post_type'] = 'event';
return $args;
}, 10, 2 );
Does anybody know why the query is not returning any posts in the front end?
I thought maybe I need to convert to a timestamp from ACF custom fields first? Something like this:
$start_date = get_field( 'event_date_start', $params['post_id'] );
$end_date = get_field( 'event_date_end', $params['post_id'] );
$start_timestamp = strtotime( $start_date );
$end_timestamp = strtotime( $end_date );
And then use these variables as the key:
'key' => '$start_timestamp ',
Any help at all would be great. Been going over and over this! Thank you so much. I am begging.
I have tried to run the code as above, I expected some of the custom post types of event to show up in the FacetWP template area according to the dropdown selections. Instead no posts show at all (they should show as some of the posts have February dates).