I've noticed that if they perform maintenance on the CMTS and my modem loses sync sometimes only one channel will be locked when service returns. A powercycle of the cable modem will usually return sync to all 3 channels.
I tried what you suggested and powered down my modem. I am now bonded to three channels again and my download speeds jumped back up to 47 Mbs, my upload speeds are 12.5 Mbs. Not bad for an Ultra customer. I will have to watch this if I ever do a large download, because that made a lot of difference. Using channels 45, 46, 47 and all three channels have a 36 DB SNR.
