Members dropdown list not showing every member

When trying to book from/against members, the dropdown list does not show all members (even after scrolling). Typing a few letters from the name shows the right members so I can continue, but it's weird.

Start by reproducing the booking flow described in issue #93 and inspect the members dropdown while scrolling and typing a name. Compare the displayed list with the available members; done means every member can be found by scrolling, while typed-name filtering continues to work.

Written by the indexing model from the issue text.