Thanks to Jared at https://theeventscalendar.com/support/forums/topic/date-filters-no-longer-working-with-latest-version-of-ecp-solution/ there is a fix for the latest version of TEC core+PRO to allow date filtering to work again

..\events-calendar-pro\src\Tribe\APM_Filters\Date_Filter.php

<?php

// look at line 69 and change
$field = 'eventStart.meta_value';

// to 
$field = 'tribe_event_start_date.meta_value';

/**********/

// look at line 69 and change
$field = 'eventEnd.meta_value';

// to 
$field = 'tribe_event_end_date.meta_value';