iOS mail app unread don’t include sub folders

Hi, I have around 30 sub folders in my exchange account but in my phone i only care about around 10 folders which I configured for push notifications so all the mails included in those 10 folders are auto downloaded without the need of getting into the folder and that works fine.

The problem comes in the “unread” mailbox, which only bring me the unread mails from inbox and not all the 10 sub folders I have configured.

I know I can go manually to Inbox folder, drag the search field down and click for unread search, but that will show me all unread mails in all 30 sub folders I have configured and not only the 10 I want.

I’m an apple user but in my company we had androids and now that I got switched to apple I’ m missing having this feature that works automatically enabled in android but i cannot find how to enable it in iOS. Thank you in advance for your help.