I have an Arcade expression that I am using within a webapp builder map popup.
I have added this expression to the title. The popup shows fine when viewing the app on a desktop. HOWEVER when viewing this map in mobile view (like the majority of our users) the arcade expression will not show within the popup title.
I thought this might be due to the number of characters in the popup title being restricted in mobile view so I tested out using another attribute. Plain attributes with more characters will appear in the popup title.
Therefore it appears to be an issue with arcade expression rather than the text size.