Oops, sorry about this. Short answer: it was not a Show 5 after all, and the new Show 8 is 2nd Gen.
I made a mistake in my post, and my old device was not a Show 5 - it was one of the old (early 2019) just plain “Show” models - it does not say which generation. It started to just shutdown without warning. It would boot up when power was removed and restored, and then it would run for an hour or two, and then later it looked like it was powered down - no display, no lights, no verbal or touch response, just dead.
We also have a plain old Echo (the tall cylinder style) from way back (early 2019), and its power supply is compatible with the Show (same voltage and amperage specs, and same connector shape), so we swapped power supplies between these two devices. The Show power supply works on the Echo with no issues (we let the Echo run on the Show’s power supply for days), and the Echo power supply works on the Show, but the Show would do the same thing with the Echo power supply - boot up fine, and then be powered off several hours later.
We thought it was toast, so we bought a new Show 8 (2nd gen) to replace it.
Then with the old Show, we “reset” the device, installed a software update, plugged it into the original power supply, and it has been running without any problem since then. But I have not tried any Alexa routines to show the cameras on the old Show that is now alive again. We’ve just moved it to another place in the house.
For the past 5-6 months at least, the old Show would try to show the camera as part of a routine, and frequently it would work and show the camera view full screen on the old Show. But more frequently it would just give up and say “the camera is not responding, check its power supply or network connection”.
But when I asked Alexa to show the cameras (on the old Show), it would generally show each camera full screen with no problem. The problem just seems to be when showing the cameras from routines, that it would usually fail, and very rarely would work.
The new Show 8 has that same hit or miss behavior now. Sometimes it will show the camera from the routine (but in small PIP mode), and sometimes it will give up. But like the old Show, if I ask Alexa to show a camera, it generally works on the new Show 8, AND it shows in full screen