Why has my Apple Music for Artists lifetime stream count decreased from last month?

I do 28-day reports on my artist's streaming catalogue. I use lifetime streams to see the total amounts per song, not just focusing on the streams from the last 28 days. I discovered on Apple Music for Artists that 26 of 53 songs had a lower historical count yesterday than 28 days ago, including one song that was down by more than 19K streams!

What is the reason for this, Apple?

The song is 2 years old and hasn't been playlisted (Apple editorial) since it was released. We don't use any 3rd party marketing or playlisting services.

There are 25 other songs with reduced counts, though not as drastic, it still demands an explanation.