A puzzle: What's going on here?

Here's a 3-day drop in rewards from 31K in daily curation-reward distribution to 17K, then to about 14/15K?

I've seen single day dips before, and they usually happened a week after website service disruptions. However, I don't think I've seen anything sustained like this since I started tracking it, last June.

The data is from here. Is this a data problem from steemdb.io, or are the numbers correct? If correct, any guesses about what's causing it? (I probably won't have time to dig further until this weekend)

I checked a bunch of high-powered voters, and they don't all show the same decline, but some do. For example, we see a similar dip if we look at the curation rewards for @upvu:

Even though, there was no dip in voting a week ago (the voting dip looks like today, and I suspect that it's just because steemdb is behind in refreshing...):

Same with @rme (curation, voting).

I assume that the rewards will return to their usual level around 30K, but I'm curious about the cause. Was there some sort of disruption that I'm unaware of last Wednesday and Thursday? Behavior change by a high-powered voter? Removal of large delegation(s) somewhere? Something else?

We also see the same dip in the #bursteem25 beneficiary rewards:

One thing to note is that I don't know how far behind SteemDB is, so today's numbers might not be complete, but I definitely think it's going to finish up on the low side.

Any thoughts?