Issue 1a (no sorting):

I get a "Match not found" message when the first selected item is "---". If I select the next item, "item1&", it finds the next two "item5&" and "item9&".

Issue 1b (no sorting):

However, when the search reaches "item9&" the search does not continue from the top. It is stuck at "item9&" because the next item is "---". If I delete the "---" item, the search restarts from the top.

Issue 2 (sorting):

I remove the "---" item (to simplify this issue) and then sort the grid like this:

If I select the first item, "item8", the first item found is "item9&".  However, nothing is found after this. It is stuck at "item9&" (note that "item9&" is the last item in the grid before sorting)