It is hard for us to tell how volatile the idx is as a selector. Sometimes you can utilize idx because the same value corresponds to the same location/item, but other times it will randomly change.
Similar to what @william.coulson mentioned, you could use a ‘find children’ activity on the parent element. Then use a ‘for each’ activity to loop through each element and pull out the text attribute. This may work all on it’s own, but sometimes there are hidden elements with blank text attributes, or other garbage data thrown in. If that’s the case, then you can add everything from the for each activity into a list, remove empty, blank, and null strings, remove duplicates, then take the last item in the list.
Let me know if you need help with any of the above and I can try and give concrete examples as I’ve done something similar a few times in the past