I don't recall that happening with my two CMs but maybe the signal drop wasn't severe enough. Yet I infrequently get an interline twitter problem that I can only clear up via a hard reset removing line power while the box is on; when it comes back on it first displays the CM screen akin to a factory reset (but it's not factory reset).
Funny your timing of this post though. Last night my Hughes DirecTV HD receiver lost an ATSC channel when a National Guard transport 'copter went over my house, this on a major station that has just recently gotten weaker*. I had to toggle power to recover (but not what I call a hard reset). Note that this receiver is of an older generation chipset than CECBs and also doesn't have their level of sensitivity.
*I've been having problems for a few years now that appears to only affect some of my majors (FOX, NBC, CBS, and PBS (although PBS can be weak to begin with ($))), all UHF but not adjacent. ABC here is on upper VHF. Now granted the other stations are UHF but I admit I don't look at them as frequently, but I do check them when this problem crops up. Only one station at a time and sticks around for weeks. Appears to get worse during the evening (of course! Prime Time) but I don't monitor it all day and night. I suspect interference from say a ham radio operator although there's plenty of other possibilities these days (flaky > utility meter RF, home automation/portable/Wi-Fi RF, cell/microwave trunk, etc.). The funny thing is my solution: two-way combine a small loop antenna adjusted for the problem channel and located near ground level (near main TV/junction) with my attic antenna (big ol' VHF-UHF array). Unless it's proximity, I'm assuming my attic antenna has too much gain per the interference.