Pete C. wrote:

Splitters are not one-way or two-way, they all will pass signals in
either direction with the same predictable loss of 3.5db per split.
Where the cheap splitters have problems is with shielding and bandwidth.

Yes, they are combiners or splitters, it doesn't matter which way the
signal goes.

Another thing to keep in mind is that many of the digital cable boxes
need to be plugged in and receiving data for quite some time before they
will work properly.

I'm pretty sure now that there's one of two problems. They may have been
distributing the digital boxes to all customers in advance of the
disabling of analog cable, even if the customer didn't sign up for the
more expensive digital service, or I didn't leave the box plugged in
long enough (about 5 minutes).