Highlight new mails in virtual folders

Hello, I have only virtual folders on the sidebar. When I receive new mails, the virtual folders containing new mails are not highlighted. Is it possible to change that ? If I use only regular folder, by starting mutt all regular folders containing new mails are highlighted. If I understand right, the virtual folders are the result of a notmuch query. My guess is: when I start mutt, I see the result of the last query. Only if change to a virtual folder the query is actualized. And it's what happens: when I change to a virtual folder containing new mail, just after changing the virtual folder is highlighted. How can I have the virtual folder highlight when I start mutt ? Thank you! Regards, Cédric