Shovill, several day run/queue for some run

Good morning, I have been using galaxy for a while since it work very welll for my research activties. Recently i am using a shovill workflow to study several sequencing results. I have noticed that the workshop remain in queue for a long time (3 days) or they run for multiple days. In other occasions this never happened, I am wondering if I am missing something. Thank you in advance for the assistance