Inconsistent typeahead when searching

**Operating System**: `Windows`

**Steps to Reproduce**:

1. Go to [DocFx documentation](https://dotnet.github.io/docfx/api/Microsoft.DocAsCode.html)
2. Type "Attr"

3. Type "Attri"

4. Type "Attribut"

**Expected Behavior**:
The same search results are returned when you continue to type a word.

**Actual Behavior**:
When searching you get typeahead suggestions after typing a couple of letters but if you continue typing the suggestions dissappear. After a few more letters suggestions can return but can be completely different.

I have the same issue for most words not only "Attrbiute" in the above example.