CM1200 - Only One Locked Upstream Bonded Channel

I had the same issue just last week and I can say it was not the equipment as I bought the CM1200 last month to replace an older nighthawk modem/router combo.  This entire time I thought the threshold of 52+ DBs was ok up to 57 DBs, but come to find out that that is the analog standard for Spectrum as explained by the technician Supervisor.  As soon as he pulled my modem's information he saw three upstream channels locked at 51.3, 51.0, and 51.8.  He said that at 52 DB on an all digital system is the threshold.  I live in NC where I guess it is all digital where I live.  The first tech that came out adjusted my upstream to 50 DBs readings, but then without being told after he left, the regional maintenance crew changed the levels for the entire area which then made my DBs go back to the readings I just mentioned before.  Then the Tech Supervisor called and pulled information from my modem after an entire day of complaining to tech support on the phone.  Simple fix too.  Your splitter on the outside of the home where the coax cable goes into the home has like 5 different connection spaces on it.  Two will be for input and output.  The other three will have different measurements for reducing the DBs on the line as I was explained.  I would suggest your tech work with the splitter as they know more about configuring the splitter to work perfectly.  All the tech supervisor did, was increase the measured reduction connection from -3 DB to -7 DB.  Now my three upstream channels are locked solid with a 47.3, 48.0, and 47.7.  A good cushion for staying under the maximum.  I subscribe for 400 Mb/sec download and 20Mb/sec upload and am reading 480 Mb/sec download and 80 Mb/sec upload tested with speedtest.net to AT&T in Mexico City, Mexico (I decided to test out of network to ensure that it is not just an in Spectrum ploy to tell me my speed is fast in the network).

Oh and believe me I thought it was a faulty modem mixed with the Orbi Mesh Router. 

Hope all is good with you all and your systems are doing well.