--snip--
Did you monitor your CPU miner a bit?
No, i didn't.
One thing I just realized is that in the screenshot, the I value (BTC per hour) is set to a question mark. So maybe it did quickly submit a block candidate and was waiting to see if it got accepted by the network? Can you post a log screenshot of what it looks like when bfgminer finds a valid block (whether it is accepted by the network or not - you mention 2 stale blocks)?
What exactly do you mean by log? I checked my Bitcoin Core log and found out older log was wiped. After quick search, Bitcoin Core has config called
shrinkdebugfile which enabled by default with 10MB limit. And few days ago i perform reindex which wipe everything from last years.