I'm using default frequency (600 MHz), and I never touched anything on the board. Also tried 500 Mhz setting just now, same difference.
It reads about 3.6 MH/s initially, but restarts begin almost immediately, so it's really hard to tell what the accurate hash rate is.
I'm 99.99% sure that this is not a power issue. Tried to connect the stick directly to different machines, tried two powered hubs, tried Lenovo dock station with 40W power supply and USB 3.0 ports - no changes. And, as I said, it all began just a few days ago - before that I had no issues at all in exactly the same configuration.
Ok. One of the things I wanted to find out with the debug mode is WHY the hashrate drops to around 2.5M/s, is it because some cores stop being activated (after a restart), is it because some data doesn't get transmitted, (USB hub clogged up has been suggested). I know it drove me mad at one point, but since now everything is stable (running 11 sticks on 1 hub at around 55Mh/s total) I am happy.
For example I noticed (via the debug mode) that sometimes bfgminer doesn't recognise the MLD serial number or even that it is a MLD connected to the COM port -- although it still works though! You can also see/check this via the [M] option (Manage device) and see if the device serial number and type comes up correctly. But when I restarted bfgminer it was ok again. This happened very repeatedly, especially when I had the restart problems. From the debugmode I saw this happened in the usb-2-serial initialisation of devices phase where bfgminer checks what's connected to each port. No idea why that happens.
So you may want to check via Manage devices in bfgminer if it your MLD is actually recognised properly or not (Should say Futurebit Moonlander and a serialnumber (long string, not the label that is on the unit). It won't resolve your problem, but every piece of the puzzle helps.