If you're having issues with your Darknode, it's always good to restart it forist prior to exploring other solutions.
To restart your darknode, open a terminal and run:
darknode restart DARKNODE NAME
Note: Restarting has been known to use a very small amount of Gas (ETH) if you are restarting around the end or beginning of an Epoch. To avoid this, only restart your Darknode once and wait at least 3 hours.