Low Search starts_with Returns All Result

Question

I've got an issue here where a low search via a select drop down is returning all results, and I am not sure why.

Here's the search form.

{exp:low_search:form result_page="{segment_1}/search" form_id="last_name_search" starts_with="search:Lastname"}
        <select name="search:Lastname" id="last_name">
            <option value="" selected>Initial Last Name</option>
            {exp:low_list:each items="A|Z" range="yes"}
                <option value="{val}">
                  {val}
                </option>
             {/exp:low_list:each}
        </select>
{/exp:low_search:form}

I need to search a members channel by querying against the first letter of their last name. To do this starts_with seemed to be the Field Search parameter that needed to be used. But, in the results tag, every member is being returned.

Here is the results tag.

{exp:low_search:results
        limit="20"
        paginate="bottom"
        query="{segment_3}"
        status="Members-id5|Staff-id7|Site_Admins-id6|Corporate-id8"}
    {!-- HTML stuffs --}
{/exp:low_search:results}

I checked {low_search_search:Lastname} and it does hold the correct lettered I want to query with, but it's not being applied to the results. What am I doing wrong here? Thanks for any help!

Answer 1

To quote the docs:

[P]arameters can be applied in two ways: as input fields in a Form, or as hard-coded parameters in the Results or URL tag.

That means the Form tag doesn't accept any filter parameters, like starts_with. So try moving that parameter to the Results tag instead.