[atlas] API probe search

When searching for specific ASN probes via: https://atlas.ripe.net/probes/ and entering a search like "ASxxxx", why does the API ignore the letters AS and respond with probes that have an id of yxxxx or xxxxy or ASN yxxxy? Shouldn't it be if I specify a specific string of ASxxx the response should be *only *those probes in ASxxx or at the worst also ASxxxy? Thanks, Hank