With a Cardinals game followed by an MLB post-season game (trying to avoid that spam link here), I have had lots of chances to admire the SA 8300HD box's tendency to slip into what I call the "5 second delay". The actual number of seconds may vary, but it's quite noticeable if you have two Cox SA boxes that can tune the HD channels. Here's a sampling of how to observe the delay:
(1) On a Cox SA8300HD with Passport Echo, tune to a program on a channel, call it channel "A". Use PIP to check the channel the other tuner is on, call it channel "B". It needs to be a different channel, not the same number or "mapped" to the same channel.
(2A) Turn the SA box off for a couple of seconds, then turn it back on (this assumes your SA box is set to power-on to the "Last Channel".
(2B) Use PIP to swap to channel "B", then swap back to "A".
(2C) Directly tune the SA box to channel "B", watch it for a couple of seconds, then switch it back to your channel "A".
(2D) Switch to 1999 to check diagnostic screens, then switch back to "A". (I'm counting this as different from 2C because 1999 isn't really a channel that uses a tuner.)
If the program you are watching on "A" has dialog at the time you switch away from it, then when you switch back you may even hear a repeat of some of the dialog you already heard.
Note that 2B and 2C are things a viewer might reasonably be expected to do, such as to check on another game on another channel.
Unfortunately, when you have entered the 5-second delay zone, pressing the "Live" button on the remote will not eject you from the zone.
To escape from the 5-second delay zone:
(3) Switch away from "A" to a different channel, not "B", and back to "A". Unfortunately, you will not be able to do this if you are recording the program on "A" -- that is, if you are recording the program you can only get back to watching the program live by stopping the recording momentarily and switching away and back.
I have a feeling there may be other ways to enter the zone, because many times when I turn on the other set, I find that I have asked the 8300HD to delay the channel I'm watching, but I'm not sure what magic I applied to accomplish that. And there may be other ways to escape from it: I just usually tune down one channel and back up. You just have to force that first tuner to clear its cache/buffer.
In the days of rabbit ears, we just didn't know how much fun we were missing, did we?