iCloud mail folders appear empty, until you click on each folder

Hello friends -

Can anyone help with this mail rules-related question?

My iCloud mail rules will push messages into various folders. However there is no "number" that appears next to a given folder after an email has arrived. So, I only know if there are messages in my folders if I click on each folder. With MacMail on the laptop it works correctly - when an email arrives, it goes to a folder and a number is added to the folder, so I know there are messages. Any ideas? It doesn't seem to work in the browser (Safari).

Thanks in advance!