As a follow up for T149435: Build user interface for the Filter Search Bar
If a user double-click (a slow double click) in the search field, the field will be outlined, indicating that the focus is on it. Start typing, e.g. 'Bot', no suggestions of filters are displays. You need to click somewhere else to make searching for filters work again.
So, the following screenshot illustrates the case - the Search field is outlined, and the cursor is in it, but suggestions are not displayed.

@Mooeypoo commented:
We seem to have an issue here with the popup ironically ignoring $autoCloseIgnore, so clicking on the input twice seems to close the popup?