From the description of half the house not working, I am guessing that the other half still does work. I am also guessing that your CM15A is on a circuit in the working half of the house. If you move the CM15A to the "non-working" side of the house, do those modules work (and the other ones not)?
As others have suggested, it sounds like it is either be a problem with your phase coupler/signal bridge/phase-to-phase signal path, or it could be a change in noise or signal-sucker levels on one phase.
If you don't have any sort of coupler, then your signals have to go out to the pole transformer, and then come back on the other phase. That can seriously degrade the signal level to the point where other noise (or signal suckers) can interfere with signal reception. Noise from other homes on the same pole transformer can also cause problems.
You may have to go through and to a "breaker box test," where you turn off one circuit at a time, and see if anything changes.
Noise can come from unexpected places. Many people here have heard my story - my problem was caused by my neighbor's failing CFL bulb. the noise level was high enough to travel from his house across the street to mine, and still was loud enough at that point to disrupt some of my devices. I had a similar problem about a year earlier with one of my own CFL bulbs, too. In both cases, they were buzzing loud enough to be heard from a few feet away. That might be another place to look for a cause.