This is a user-to-user forum, and Comcast has different channel line-ups in different markets around the U.S. It is likely that Comcast chose to "bump" CMT to a hgher service tier than the one you subscribe to.
If you search this forum, you will see a huge number of posts complaining about Turner Classic Movies (TCM), which in some markets was included in the Digital Starter tier but was "bumped" to Digital Preferred.
Those are business decisions that Comcast makes. In my area (Greater Seattle), Comcast generally DOES notify subscribers of channel line-up changes in advance, but I do not know if that is true in other areas of the U.S. Even when they do "provide notice", a lot of viewers don't read their monthly bills in detail and are caught by surprise when a favorite channel is no longer available without purchasing a more-expensive package.
jpr2238 wrote: I still have cmt on main modem, but, 3 tv's with adapters does't have cmt. WHY
If CMT has been moved to Digital Preferred in your area, and you subscribe to Preferred, then you would still get it on a full set-top box. But the small DTA boxes only get Digital Starter channels. They cannot tune to channels in any higher tier. If you want to watch Preferred channels on your other sets you would need to rent additional full set-top boxes.
Okay, it's my fault for not reading my bill closer and remembering they were going to move CMT from digital starter to preferred package. but I've been able to watch CMT since it started whenever that was. I'm one more disappointment from dropping Comcast. Maybe I should just drop now and save one more disappointment. At least you all were helpful to make me dig out my old bills and read them closer. Consider me a short-timer.