It appears there is a bug that affects SP35 PSUs. The PSUs appear to not notify the mining software properly when they encounter trouble (such as overloading), which results in the mining software not reinitializing that PSU. When this happens, one PSU and one hashboard will sit idle until the user manually restarts minergate. Zvisha is aware of this issue now, and will probably have a firmware fix for us soon. If you have received an SP35, I suggest checking on it frequently for the next few days. It might also be a good idea to drop the PSU limits by 50 watts until a fix is released.
Our units have this as well. Can confirm dropping PSU wattage fixes it.
There is new experimental FW 2.5.40.
In the "settings->advanced" you can set "Restart miner if rate below". You can set it to 3000, and see if this will help you monitor miners from such failures. Dont change the "FPGA serial speed".