I have been monitoring this every day for over a month. I use "Find Other Computers" to check status then "Clear History".
What I have found is A6 in red and A1 and P16 in red with a question mark each time. I turn the computer connected to AHP off every night and on again in the morning. I have also checked during the day and when I reboot during the day. These three codes seem to be triggered by the powering up and down sequence. I do not leave AHP running unless I'm checking something or doing maintenance. Starting and stopping AHP does not seem to trigger the codes.
The first three weeks of the test I found that G7, M1, and M13 were in red about 1/2 the time plus N1 a single time. Since my USB cable is 16 feet long, the maximum leangth, I put RF filters around the cable at both ends and continued the testing.
Two weeks of additional data show A1, A6 and P16 still doing the same thing every day but G7 incidents have been cut in half. K14 has shown up 3 times and N1 a single time.
In my opinion A1, A6 and P16 are built in artifacts of the relationship between the host computer and the CM15A and the other codes are line noise unique to my house since none of my neighbors have X10.
By the way can someone explain what the question marks in the red squares on A1 and P16 mean in the Find Other Computers report?