I didn't check a couple of days ago so maybe it happened then, but it looks like Ocean only shows up in the top 10 for the past 24 hours because binance pool and brains -- who usually measure more success than Ocean -- got particularly unlucky today and brought down the total measured hashrate.

Ocean, meanwhile, slightly overperformed, but that part doesn't look like it really mattered to their ranking -- even if they only produced as many blocks as expected per their self reported hashrate, they would still be in the top 10 today because not as many blocks were produced today as one would expect, and that is also due to Binance and Braiins being unlucky today.