Rogue 3024 MPPT Charge Controller Issues

Installed this charge controller to govern my battery banks and has worked well, however, there are times when it apparently disengages, stops working, most recently noted during a visit today (wintertime in New Brunswick, Canada). My alarm system had indicated an interruption in power at some point since our last visit about a month ago. It was about noon when I checked my Trimetric meter it indicated my banks were fully charged at 101%of capacity. Sun was shining, my array was at the winter tilt, so the reading was not surprising. I went upstairs to check the Rogue controller, thought it was sleeping but when I touched the button which normally would show me the daily readings, the light came on, but no one was home, there were no digits or anything on the screen. I tapped a few of the other buttons and a bunch of mumbo-jumbo came up which appeared incomplete and, in any case, I could not make it out - never saw that kind of display before. I shut off the breaker running from the controller to the battery banks, waited a couple of seconds and flipped it back on. After a minute or so, the normal display came on the screen. I checked the history on the controller to find that my bank has been regularly charged to full during our absence.

When I contacted Rogue, the technician had heard of similar problems supposedly in winter, but didn't know for sure what the issue could be, possible causes blamed on poor sun, low voltage, undercharged batteries, essentially they don't have any idea.......Did my research before purchasing this unit, thought it was high quality, has been in operation for eight months with no real problems until now. Technician is telling me he thinks if the unit was not booting up when I got there, it probably was not functionally properly or protecting my banks??????????????????????? Not a good situation if you want to avoid overcharging.

Does anyone have any similar experiences, advice, opinions, any help would be appreciated, thanks.