[Web API] No Search Results for ISRC

[DONTBLINKMUSIC]

We are using the Web API to find tracks by ISRC, however some tracks are not being returned correctly. Here an example:
QZHZ62065915

Fetching this ISRC returns no results, though it should return the following track:

78qLM2KxZajhZnkYTEV8Q5

I assume it's because this track is not available in any markets? I still think that it should be returned anyway!