0.6 suffers from the very same stability issues. works nicely when I start it, come back after an hour an all cards are showing 0.0Sol/s.
Use the -f 2 option and a goto loop in the batch file. I also have a watchdog daemon to monitor power consumption of my rigs and restart them when the power consumption is too low. Works like a charm. I'm getting 35-40 sol/s stable with RX 480 and 0.6.