When you place the item on the report, it defaults to WordBox.
...
When you place the item on the report, it should default to a particular object type based on the data type
e.g. integer, decimals etc become DecimalFormatBox
strings and long chars become WordWrapBox
short chars become WordBox
etc
I can't recall the trigger point that defines what a short and long char is, it something like 25 or 30 characters.
So I'm curious that this hasn't defaulted to WordWrapBox. What is the datatype, or what version of Studio, Genero Report Designer are you running?
Similarly when you tried adding a WordWrapBox manually what was the value of X-size attribute. This defaults to width("M")*20. So again I am curious that when you added the WordWrapBox yourself, it didn't wrap.
Reuben