There are several factors that streaming services use to calculate royalties.
Some streaming companies might not pay royalties for listeners who are on a free trial or other promotion. Other services (like Spotify) say that they split the revenue pie on a country-by-country basis. So if the stream happens in a smaller country where there are few Spotify subscribers or ads, it seems the payments may be smaller or nonexistent. Note that we can't speak for Spotify or other streaming services--this is just speculation.
DistroKid passes on 100% of whatever earnings the stores send us for your sales/streams. You may need to Google around and/or check their FAQs for current rates.