Users. The search doesn't work for first letters

AR: there are no users shown when you search by first letter.
ER: whatever you input into search field, it should look for any part of the name - not only those letters that are in the middle.
Steps to reproduce:

1. Add user 'Andy'
2. Type in the search field 'a'
3. You'll see that Andy won't be found, only those users are found where they have 'a' in the midst of the name.