Collection Element not visible!

Hi Experts!

Can anyone help in regard to this issue. We have a collection plan which has multiple collection elements. We can see those elements in the quality result entry/update screen but they are missing in the collection plan setup screen. We can see just one element in the setup screen. Those invisible elements are not even available in the collection element setup screen.

While searching in the collection element setup screen few elements show in the list of value but while hitting the find button it says "query caused no result to be retrieved". Few are not even available in lov.