Inventory search results are rendered inconsistently

While trying a couple of different searches for things in inventory I noticed some inconsistent behaviour in how the results list behaves.

Step to reproduce:

1. Login to the bugfest environment and go to https://bugfest.folio.ebsco.com/inventory/view?qindex=all&query=java&sort=Title
2. Notice how the search results (~470 of them) are rendered so that they fill the pane vertically.
3. Search for computers with the dropdown set to "All"

What should happen: The results from the last seach should be distributed the same way as in the first search.

What actually happens: Only half the pane is filled with results and no visible sign of that this is not the complete result, except for the count just abouve the pane stating 500 records were found.
NOTE: refreshing the page redraws the resultlist and it now both fills the entire pane with results and shows a scrollbar.