I have been studying the block history for P2Pool here:
http://p2pool.org/stats/?blockoffset=40
over the last several days. I noticed that bitcoin reward for each recent block is blank until 459871 and previous blocks (which appears after scrolling through several pages of block history). Once you get to block 459871, it shows mining rewards as I'd expect. Can someone help me understand why this is? I have been mining on the site for quite some time with some S9s and still haven't received a reward. I'm wondering if this might be the cause?