I'm testing my l3+ with the new 1.0 stable version and every time I restart the miner, after some minutes it begins to mine the dev fee.
I have selected the option "Mine dev fee daily instead of every 2 hours".
While still tuning / restarting a lot, please don't use the the daily option as it will always start with the devfee after 5 minutes. Once you found your settings, the daily option is the most effective.