Sandbox search/companies endpoint returns an empty response

Hello everyone,

We are using the Companies House sandbox ( to generate test data for developing and testing.

Test company generates and gets by ID very well (“company_number”: “25676636”).

But when we are trying to use the search company by company name ( 25676636 LIMITED), we are receiving an empty response (“total_results”: 0).
The same thing when we are trying to get the persons-with-significant-control-statement ({}).

What are we doing wrong?
How can we use the search endpoint to receive test data by name?