Suppose your miner node found pow2, but your total_missed count increased, instead of generating a block.
If this happens, double check your keys used in the config.ini file.
witness = "minerwitness"
miner = ["minerwitness","WIF_ACTIVE_PRIVATE_KEY"]
miner = ["miner1","WIF_ACTIVE_PRIVATE_KEY"]
miner = ["miner2","WIF_ACTIVE_PRIVATE_KEY"]
miner = ["miner3","WIF_ACTIVE_PRIVATE_KEY"]
mining-threads = 4
private-key = WIF_SIGNING_PRIVATE_KEY
Using keys without paying attention to their roles is a common mistake. 
that issues with missing blocks tend to happen when you are using an account that was created through steemit.com but seems to work for the mined account.
So erroneous configuration might work for your mined account by pure coincidence. In other words, the same key has been defined for all roles, so: WIF_ACTIVE_PRIVATE_KEY is exactly the same as WIF_SIGNING_PRIVATE_KEY.
If you believe this idea is of use and value to Steem, please vote for me as a witness
either on Steemit's Witnesses List
or by using your cli_wallet command:
vote_for_witness "YOURACCOUNT" "gtg" true true