Concept selections in "Pick from existing" disappear if user extends list length

GIF: See attached.

Steps:

1. Create a new concept using the "Pick from existing" workflow
2. Select a concept (e.g. "Weight")
3. See your concept is highlighted and you have 1 concept picked
4. You need to see more in the list, so you click to expand the list to show more results (e.g. from 10 --> 100 in the list)
5. See your concepts that you have picked already are suddenly de-selected

Expected: My already-selected concepts should remain selected, even if I increase the list length, or if I go to the next page in the list, so that I don't have to re-do this process many times for small numbers of concepts at a time.