It causes fatal errors on Rank Math

Hi,

the plugin is generating fatal errors on Rank Math because seems to filter with null values some hooks, this is an example:

On ActionScheduler_QueueCleaner.php on line 34 the variable $lifespan is null causing the fatal error:

public function delete_old_actions() {
$lifespan = apply_filters( ‘action_scheduler_retention_period’, $this->month_in_seconds );
$cutoff = as_get_datetime_object($lifespan.’ seconds ago’);

This doesn’t happen when Cleanup Action Scheduler is disabled.