I've extended delivery schema with fields "utm_campaign" and "utmSource" and when I try to use them, for example populate in delivery text (for testing) they are not visible in email client but they are visible in webview. What is interesting is that this is not happening when use out of the box fields of delivery, for example "title" displays everywhere properly... So from the code below only delivery title is displayed in both email client and webview. The other two works only in webview. Any ideas what might be causing this?
To anyone interested it started to work the day after. Did this update on other environment and the same story. So probably some process needs to run overnight to update generating the deliveries... kind of weird but at least works now.