1910 Census Search problem on Ancestry

I went to the FHC today to look at the 1910 Every Name Index on Ancestry.com for some of my families. I didn't count on having problems with the Index, and am wondering if others have experienced the same thing.

If I put in a given name and surname, I get useful results.
If I put in the given name, surname and a state, I get zero results.
If I put in the given name, surname and birthplace state, I get zero results.
If I put in the given name, surname and a year of birth, I get useful results.
If I put in the given name, surname and gender, I get zero results.
If I put in the given name, surname and race, I get zero results.

I tried all of that with John Smith as the name. I get the same pattern of results if I put in just a given name or just a surname, or wild cards for either or both of the names.

Using the 1900 and 1920 indexes on Ancestry, I get results for every combination listed above.

I think that the Ancestry subscription at the FHC is different from the Ancestry home subscription that many of us have (but I don't have yet). I'm wondering if Ancestry has a problem with the library subscription part of their service.

Has anyone else experienced this, or know what to do about it?