List but not a list?

I'm using an xml reader to read multiple xml files into fme, each xml file is translated as one feature with a number of attributes. In some of these files there are multiple instances of the same element and these appear to be formulated as a list when inspecting (e.g. displayed as date{0} and date{1}. However if I try and do anything with this list, e.g. explode/concatenate, I just get a no list attributes available message.

 

 

I suspect this is something to do with the fact that the attribute is not always a list element as if i read just one file that I know to have multiple instances of the same element I can manipulate lists no problem but I've got no idea how to resolve this.