My system is working fine and my 99, 101, 103 signal strengths are all 93 or higher, but I noticed that when I checked my SWM signal strengths, two of them read as zero with all the others at 100. Is that normal? I don't have any issues at all. I have Whole Home DVR and everything works fine? Is this a case of 'if it ain't broke don't fix it', or should I address the issue?