Same search item with different result?

Hello:

Recently I meet a strange problem.
I have two github accounts: github.com/retanoj and github.com/1uanWu .

Both of them visited same url “https://github.com/roderickhsiao/So-You-Think-You-Can-Dance/search?q=“momo.com”” but got different result.

It just likes “retanoj” searched the exact item "momo.com" (with quotes) and got zero results. But “1uanWu” seached the fuzzy item momo.com (without quotes) and got 101 results.

What happened?