looks like newlines have been allowed in trigger expressions somewhere between 2.2 and 2.4 - but i was unable to find that change explicitly listed in the changelog, whatsnew pages or specifications. the most suspect issue is ZBXNEXT-1782, as it's spec says "The validator should also support \r, \n and tab characters same way as spaces."

if so, this should be added to the 2.4.0 whatsnew page and the changelog as a separate entry. suggested wording : "added support for newlines and tabs in trigger expressions" or similar