Repeating attributes never get added to the Attributes listing on that tab. Probably in part because it would be impossible to read their names - an attribute in a repeating section has a full name that looks something like repeating_section_-56hg7rb75bnh9_attribute_name. But mainly because those attributes a special dynamic attributes, that aren't like other attributes.
The Attributes listing on that tab is a holdover to the time before we had the character sheet tab. If you're using a character sheet, you shouldnt be using the Attributes listing - unless you want to add custom attributes that aren't in the character sheet.
What are you trying to do with chatSetAttr?