For InstantSearch v3
The uiState only works when the widgets responsible for each UI state attribute are mounted. For instance, a searchBox widget is necessary to provide a query.
For InstantSearch v4 and later
The uiState passed to initialUiState or via routing needs to be nested per index. For example, if you only have a root index called “instant_search”, you should use a value like { instant_search: { query: 'query' } }.